Methods and devices for applying localized thermal therapy

ABSTRACT

Methods and devices are disclosed herein that generally involve applying thermal therapy to tissue (e.g., localized cooling or heating of tissue), and in particular applying thermal therapy to the spinal canal, tissue disposed within the spinal canal, and/or nerve roots extending from the spinal canal. In some embodiments, tissue can be cooled or heated by implanting or positioning a thermal device in proximity to the targeted tissue. A number of exemplary thermal devices are disclosed, including bone anchors, inserts for use with bone anchors, K-wires, bone anchor extensions or towers, cross-connectors, spinous process plates, spinal rods, pedicle markers, bone taps, drill bits, bone plugs, bone plates, clamps, interbody or disc implants, thermal pads, and tubing loops. The thermal device can be left in place following surgery to facilitate application of post-surgical thermal therapy. In some embodiments, the thermal device can be removed post-surgery in a minimally- or non-invasive manner.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/487,802, filed Sep. 16, 2014, which claims the benefit of U.S.Provisional Application No. 61/878,166, filed Sep. 16, 2013 and U.S.Provisional Application No. 61/878,168, filed Sep. 16, 2013, each ofwhich is hereby incorporated by reference herein in its entirety.

FIELD

Methods and devices for applying localized thermal therapy are disclosedherein.

BACKGROUND

According to the National Spinal Cord Injury Statistical Center, thereare more than 259,000 people living with a spinal cord injury in theUnited States. Traumatic spinal cord injury afflicts around 15,000people in the United States each year. Approximately 12,000 survive thecord injury with a neurological deficit, which is commonly a severe,disabling physical impairment and mental burden. Long-term care for cordinjuries costs an estimated $9.7 billion annually in the United States.

Application of certain degrees of hypothermia to a patient's spine andspinal cord after a spinal cord injury can lead to benefits, such as areduction of the metabolic demand of spinal cord cells, reduction ofedema, added tolerance to hypoxia/ischemia, and ultimately a reductionin spinal cord tissue damage or cell death. Realizing these benefitscould mean the difference between quadriplegia and being able to useone's arms. The use of a cooling effect for these purposes can bereferred to as therapeutic hypothermia.

Besides traumatic spinal cord injury, the spinal cord can be injured dueto surgical procedures such as abdominal aneurysm repair, wherein bloodflow to the spinal cord is reduced. This lack of blood flow, also knownas ischemia, can cause cellular damage to the spinal cord. Local coolingof the spinal cord can decrease the incidence of spinal cord injury inabdominal aneurysm surgery. Nerve roots or any member of the centralnervous system in the spine can also become damaged from trauma and/orsurgical insult, and can cause neurologic deficits and/or significantpatient pain. It will be appreciated that the spinal cord and nerves canbecome injured through any number of means.

Existing methods for cooling the spine involve systemic cooling of theentire body. Such treatments carry a number of disadvantages. For onething, systemic cooling techniques lack the ability to specificallytarget the injured tissue and, as a result, other unrelated tissue canbe damaged or destroyed by the cooling. Systemic cooling can also causea wide variety of side effects. In addition, the degree to which thebody can be cooled systemically is very limited, and it is difficult toprecisely control the degree to which the body is cooled in systemicapproaches. Body temperature changes using systemic techniques also tendto occur very slowly, which can undesirably delay administration of acooling effect to the injured tissue.

In some instances it can be desirable to apply localized heating ortherapeutic hyperthermia to a patient.

There is a continual need for improved methods and devices for applyingthermal therapy.

SUMMARY

Methods and devices are disclosed herein that generally involve applyingthermal therapy to tissue (e.g., localized cooling or heating oftissue), and in particular applying thermal therapy to the spinal canal,tissue disposed within the spinal canal, and/or nerve roots extendingfrom the spinal canal. In some embodiments, tissue can be cooled orheated by implanting or positioning a thermal device in proximity to thetargeted tissue. A number of exemplary thermal devices are disclosed,including bone anchors, inserts for use with bone anchors, K-wires, boneanchor extensions or towers, cross-connectors, spinous process plates,spinal rods, pedicle markers, bone taps, drill bits, bone plugs, boneplates, clamps, interbody or disc implants, thermal pads, and tubingloops. The thermal device can be left in place following surgery tofacilitate application of post-surgical thermal therapy. In someembodiments, the thermal device can be removed post-surgery in aminimally- or non-invasive manner.

In some embodiments, a thermal device includes a connector configured tocouple a first spinal fixation rod to a second spinal fixation rod, theconnector having a first recess formed therein configured to receive afirst spinal fixation rod and a second recess formed therein configuredto receive a second spinal fixation rod; a delivery conduit extendingfrom the connector and being configured to supply a thermal medium to achamber formed in the connector; and an exhaust conduit extending fromthe connector and being configured to withdraw the thermal medium fromthe chamber. The chamber can be or can include an inflatable memberconfigured to expand outward from the connector when inflated with thethermal medium. The inflatable member can be configured to protrudethrough a window formed in a sidewall of the connector when inflatedwith the thermal medium. At least one of the delivery and exhaustconduits can be attached to the inflatable member such that removingsaid at least one of the delivery and exhaust conduits from the thermaldevice is effective to remove the inflatable member from the thermaldevice. A lower surface of the connector can be concave and configuredto receive at least a portion of a patient's dura therein. The deliveryand exhaust conduits can be selectively detachable from the connector.The delivery and exhaust conduits can be formed by inner lumens of amulti-lumen conduit.

In some embodiments, a method of applying localized thermal therapyincludes coupling a connector to a first spinal fixation rod and to asecond spinal fixation rod secured to a spine of a patient such that acavity formed in the connector is disposed adjacent to a spinal canal ofthe patient; and delivering a thermal medium to the cavity to apply athermal effect to the spinal canal of the patient. Delivering thethermal medium can include supplying a heated or cooled fluid to thecavity to expand an inflatable member of the connector into contact withor into close proximity to the spinal canal. The first rod can bedisposed on a first side of a midline of the patient's spine and thesecond rod can be disposed on a second, opposite side of the midline ofthe patient's spine. The method can include positioning the connectorsuch that at least a portion of the patient's spinal cord is receivedwithin a concave recess formed in a lower surface of the connector.Delivering the thermal medium can include supplying a heated or cooledfluid to the cavity through a delivery conduit coupled to the connectorand in fluid communication with the cavity. The method can includeclosing an incision around the delivery conduit such that the deliveryconduit extends out of the patient while the connector remains implantedin the patient. The thermal medium can be delivered after closing theincision. The method can include decoupling the delivery conduit fromthe connector after closing the incision and pulling the deliveryconduit through the closed incision to remove the delivery conduit fromthe patient. Removing the delivery conduit can include removing aninflatable member attached to the delivery conduit.

In some embodiments, a thermal device includes a bone anchor having aproximal head and a distal shank, the proximal head having first andsecond opposed arms that define a rod-receiving recess therebetween; afluid inlet pathway that extends through at least one of the first andsecond arms; a fluid outlet pathway in fluid communication with thefluid inlet pathway and that extends through at least one of the firstand second arms; a delivery conduit configured to be selectively coupledto the proximal head and to supply a thermal medium to the fluid inletpathway; and an exhaust conduit configured to be selectively coupled tothe proximal head and to withdraw the thermal medium from the fluidoutlet pathway. The fluid inlet pathway can extend through the firstarm, through a base of the proximal head, through a plug disposed in acannulation of bone anchor, and through a tube that extends distallyfrom the plug within the cannulation of the bone anchor. The fluidoutlet pathway can extend through a cannulation of the bone anchor,through a plug disposed in the cannulation, through a base of theproximal head, and through the first arm. The fluid inlet pathway andthe fluid outlet pathway can extend only through one of the first andsecond arms. The distal shank can be polyaxially movable with respect tothe proximal head. The fluid inlet pathway can extend through the firstarm, through a base of the proximal head, through a plug disposed in acannulation of bone anchor, and through a tube that extends distallyfrom the plug within the cannulation of the bone anchor. The fluidoutlet pathway can extend through the cannulation of the bone anchor,through the plug disposed in the cannulation, through the base of theproximal head, and through the second arm. The device can include aconnector from which the delivery and exhaust conduits extend, theconnector being configured to be selectively coupled to at least one ofthe first and second arms to place the delivery and exhaust conduits influid communication with the fluid inlet and outlet pathways,respectively. The connector can include one or more mating featuresconfigured to align the connector with at least one of the first andsecond arms and to couple the connector to said at least one arm. Theconnector can be configured to mate with a proximal-facing surface of atleast one of the first and second arms. The connector can include anelongate sleeve through which the fluid delivery and exhaust conduitsextend. The device can include a plug disposed in the bone anchorthrough which the fluid inlet and fluid outlet pathways extend, the plugbeing disposed distal to a driving interface of the bone anchor.

In some embodiments, a thermal device includes a bone anchor having aproximal head and a distal shank, the proximal head having first andsecond opposed arms that define a rod-receiving recess therebetween; atleast one cut-out formed in the proximal head beneath the rod-receivingrecess; a plug disposed within the bone anchor beneath the rod-receivingrecess; a fluid inlet pathway that extends through the plug; a fluidoutlet pathway in fluid communication with the fluid inlet pathway andthat extends through the plug; a delivery conduit extendinglaterally-outward from the plug through the at least one cut-out, thedelivery conduit being configured to supply a thermal medium to thefluid inlet pathway; and an exhaust conduit extending laterally-outwardfrom the plug through the at least one cut-out, the exhaust conduitbeing configured to withdraw the thermal medium from the fluid outletpathway. The at least one cut-out can include only a single cut-outthrough which the delivery and exhaust conduits extend. The at least onecut-out can include first and second opposed cut-outs, the deliveryconduit extending through the first cut-out and the exhaust conduitextending through the second cut-out.

In some embodiments, a thermal device includes a plug having a distalprojection and first and second lateral extensions, the plug beingconfigured to be received within a head portion of a bone anchor suchthat a fluid-tight seal is formed between the distal projection and acannulation of the bone anchor and such that the first and secondlateral extensions are seated within a rod-receiving recess of the boneanchor; a delivery conduit extending from the plug, the delivery conduitbeing configured to supply a thermal medium to a fluid inlet pathwayformed in the plug; and an exhaust conduit extending from the plug, theexhaust conduit being configured to withdraw the thermal medium from afluid outlet pathway formed in the plug.

In some embodiments, a method of applying localized thermal therapyincludes implanting a bone anchor a bone structure of a patient;attaching a connector having fluid delivery and exhaust conduits coupledthereto to the bone anchor to place the fluid delivery and exhaustconduits in fluid communication with fluid inlet and outlet pathwaysformed in the bone anchor, respectively; and circulating a cooled orheated fluid through the bone anchor via the delivery and exhaustconduits to applying a thermal effect to the bone anchor, the bonestructure of the patient, and tissue adjacent to said bone structure.Attaching the connector can include attaching the connector to a headportion of the bone anchor such that a distal-facing surface of theconnector abuts a proximal facing surface of the head portion of thebone anchor. The method can include seating a spinal fixation element ina rod-receiving recess defined in a head portion of the bone anchorprior to attaching the connector. The circulating can includecirculating the fluid only through a proximal head portion of the boneanchor. Attaching the connector can include seating the connector in arecess formed in the bone anchor such that the delivery and exhaustconduits extend through at least one cut-out formed in the bone anchorbeneath a rod-receiving recess defined in the bone anchor. The methodcan include seating a spinal fixation element in the rod-receivingrecess after attaching the connector. Attaching the connector caninclude seating the connector such that a distal projection of theconnector forms a seal with a cannulation of the bone anchor and suchthat first and second lateral extensions of the connector are seatedwithin a rod-receiving recess of the bone anchor. The method can includeclosing a skin incision through which the bone anchor is implanted inthe patient such that the delivery and exhaust conduits extend throughthe incision and circulating the fluid after closing the skin incision.The method can include detaching the connector from the bone anchor andremoving the connector from the patient after closing the incisionwithout re-opening the incision. The method can include using theconnector to manipulate the position of the bone structure prior to,during, or after circulating the fluid. The method can includedelivering an implant through the connector prior to, during, or aftercirculating the fluid. The implant can be or can include a fixation rodand the method can further include coupling the fixation rod to the boneanchor to which the connector is attached.

In some embodiments, a thermal device includes a cylindrical insertsized and configured for placement into a cannulation of a bone anchor,the insert including first and second concentric tubes, an interior ofthe first tube defining an inner chamber and a space between the firstand second tubes defining an outer chamber, the inner and outer chambersbeing in fluid communication with one another at a distal end of thefirst tube; a delivery conduit coupled to the insert and in fluidcommunication with the inner chamber, the delivery conduit beingconfigured to supply a thermal medium to the inner chamber; and anexhaust conduit coupled to the insert and in fluid communication withthe outer chamber, the exhaust conduit being configured to withdraw thethermal medium from the outer chamber.

In some embodiments, a thermal device includes a bone anchor having acannulation formed therein; a cylindrical insert sized and configuredfor placement into the cannulation of the bone screw, the insertincluding a first tube having an open distal end, an interior of thefirst tube defining an inner chamber and a space between the first tubeand the cannulation of the bone anchor defining an outer chamber, theinner and outer chambers being in fluid communication with one anotherat a distal end of the first tube; a delivery conduit coupled to theinsert and in fluid communication with the inner chamber, the deliveryconduit being configured to supply a thermal medium to the innerchamber; and an exhaust conduit coupled to the insert and in fluidcommunication with the cannulation of the bone anchor, the exhaustconduit being configured to withdraw the thermal medium from the outerchamber. The device can include a cap disposed in the cannulation of thebone anchor to seal a distal end of the cannulation. The cannulation canextend only partially through the bone anchor such that a distal end ofthe bone anchor is closed.

In some embodiments, a thermal device includes a bone anchor having aproximal head, a distal shank, and a thread formed on at least a portionof the distal shank; a fluid chamber defined within the thread; adelivery conduit coupled to the device and in fluid communication withthe chamber, the delivery conduit being configured to supply a thermalmedium to the chamber; and an exhaust conduit coupled to the device andin fluid communication with the chamber, the exhaust conduit beingconfigured to withdraw the thermal medium from the chamber. The chambercan be defined only within the thread and can not extend into the distalshank.

In some embodiments, a method of applying localized thermal therapyincludes positioning a distal end of a guide wire in a bone structure ofa patient; advancing a cannulated bone anchor over the guide wire suchthat the guide wire extends through the cannulation of the bone anchor;implanting the bone anchor in the bone structure; and applying a thermaleffect to a proximal end of the guide wire to heat or cool the guidewire, the bone anchor, the bone structure of the patient, and tissueadjacent to said bone structure.

In some embodiments, a method of applying localized thermal therapy,includes implanting a bone anchor in a bone structure of a patient;inserting a solid thermally-conductive member into a cannulation of thebone anchor; and applying a thermal effect to a proximal end of thethermally-conductive member to heat or cool the thermally-conductivemember, the bone anchor, the bone structure of the patient, and tissueadjacent to said bone structure.

In some embodiments, a thermal device includes a first plate having asuperior wing portion and an inferior wing portion, the first platebeing configured for placement against lateral sides of superior andinferior spinous processes; a bridge extending laterally from the firstplate and defining a chamber therein; a delivery conduit extending fromthe bridge, the delivery conduit being configured to supply a thermalmedium to the chamber; and an exhaust conduit extending from the bridge,the exhaust conduit being configured to withdraw the thermal medium fromthe chamber. The device can include a second plate from which the bridgeextends laterally, the second plate having a superior wing portion andan inferior wing portion, the second plate being configured forplacement against lateral sides of superior and inferior spinousprocesses such that said spinous processes are disposed between thefirst and second plates and such that the bridge is disposed betweensaid spinous processes. The chamber can extend into at least one of thefirst and second plates. The chamber can extend into the superior andinferior wing portions of at least one of the first and second plates.

In some embodiments, a device includes a first plate having a superiorwing portion and an inferior wing portion, the first plate beingconfigured for placement against lateral sides of superior and inferiorspinous processes; a bridge extending laterally from the first plate;and a second plate having a superior wing portion and an inferior wingportion, the second plate being configured for placement against lateralsides of superior and inferior spinous processes such that said spinousprocesses are disposed between the first and second plates and such thatthe bridge is disposed between said spinous processes; wherein thebridge is slidably received within an opening formed in the second platesuch that a distance between the first and second plates can be adjustedby sliding the second plate along the bridge. The device can include atleast one locking screw threadably mounted in the second plate such thatthe at least one locking screw can be advanced into engagement with thebridge to lock a position of the second plate relative to the bridge.The at least one locking screw can include first and second lockingscrews and a longitudinal axis of the first locking screw can extend atan oblique angle to a longitudinal axis of the second locking screw. Thedevice can include a temperature sensor embedded in at least one of thefirst plate, the second plate, and the bridge. The temperature sensorcan extend anteriorly from the bridge towards a spinal canal when thefirst plate is positioned against lateral sides of superior and inferiorspinous processes. The temperature sensor can be or can include aflexible contact.

In some embodiments, a method of applying localized thermal therapyincludes removing at least a portion of the cortical bone of a spinousprocess to form a decorticated portion of the spinous process;positioning a plate in contact with the decorticated portion of thespinous process; and applying a thermal effect to the plate to heat orcool the spinous process and a spinal canal adjacent thereto. The methodcan include measuring a temperature using a temperature sensor embeddedin the plate.

In some embodiments, a method of applying localized thermal therapyincludes forming an incision in a patient to access a spinous process ofthe patient; positioning a plate in contact with the decorticatedportion of the spinous process, the plate having at least one conduitextending therefrom through which a thermal effect can be applied to theplate; closing the incision around the at least one conduit such thatthe at least one conduit extends out of the patient; and after closingthe incision, applying a thermal effect to the plate to heat or cool thespinous process and a spinal canal adjacent thereto. The method caninclude decoupling the at least one conduit from the plate after closingthe incision and removing the at least one conduit through the closedincision.

In some embodiments, a thermal device includes an elongate shieldconfigured to be positioned over a midline of a patient's spinal canal,the shield including a superior flange having an opening formed thereinthrough which a bone anchor can be received to couple the shield to asuperior vertebra and an inferior flange having an opening formedtherein through which a bone anchor can be received to couple the shieldto an inferior vertebra; a delivery conduit extending from the shield,the delivery conduit being configured to supply a thermal medium to achamber formed in the shield; and an exhaust conduit extending from theshield, the exhaust conduit being configured to withdraw the thermalmedium from the chamber. The shield can have a width of at least about15 mm.

In some embodiments, a method of protecting a spinal canal and applyinglocalized thermal therapy includes positioning a plate over a spinalcanal such that a longitudinal axis of the plate is substantiallyparallel to a longitudinal axis of the spinal canal; attaching asuperior flange of the plate to a superior vertebra using at least onebone anchor; attaching an inferior flange of the plate to an inferiorvertebra using at least one bone anchor; and applying a thermal effectto the plate to apply localized thermal therapy to the spinal canal.Positioning the plate can include positioning the plate over a midlineof the spinal canal. Positioning the plate can include positioning theplate laterally offset from a midline of the spinal canal on a firstside of the spinal canal and positioning a second plate laterally offsetfrom the midline of the spinal canal on a second, opposite side of thespinal canal.

In some embodiments, a method of applying localized thermal therapyincludes implanting a first bone anchor in a first vertebra; implantinga second bone anchor in a second vertebra; seating a first spinal rodwithin rod-receiving recess formed in proximal heads of the first andsecond bone anchors; seating a second spinal rod within outriggersextending laterally outward from the proximal heads of the first andsecond bone anchors; and at least one of: delivering a thermal mediumthrough a delivery conduit to a chamber formed in the first spinal rodto apply a thermal effect to the first spinal rod; and delivering athermal medium through a delivery conduit to a chamber formed in thesecond spinal rod to apply a thermal effect to the second spinal rod.

In some embodiments, a thermal device includes an elongate shaft havinga chamber defined therein and a distal end configured for insertion intobone; a thermal source configured to deliver a thermal medium to thechamber of the elongate shaft to apply a thermal effect to the elongateshaft. The elongate shaft can be or can include at least one of apedicle marker, a bone tap, and a drill bit. The elongate shaft can berigid along its entire length. The elongate shaft can have a lengthsufficient to extend from a bone opening in which the distal end of theelongate shaft is disposed to a location proximal to a skin surfaceoverlying said bone opening.

In some embodiments, a method of applying localized thermal therapyincludes advancing an elongate shaft into a bone structure of a patientsuch that a distal end of the shaft is positioned in a bone openingformed in the bone structure and a proximal end of the shaft is disposedoutside of the patient; and applying a thermal effect to the elongateshaft to apply localized thermal therapy to the bone structure andtissue adjacent thereto. Applying the thermal effect can includecirculating a heated or cooled fluid through a chamber formed in theelongate shaft.

In some embodiments, a thermal device includes a bone plug having anon-threaded cylindrical distal projection configured to be received ina bone hole and a proximal body portion, the bone plug defining achamber therein; a delivery conduit extending from the proximal bodyportion, the delivery conduit being configured to supply a thermalmedium to the chamber; and an exhaust conduit extending from theproximal body portion, the exhaust conduit being configured to withdrawthe thermal medium from the chamber. The proximal body portion caninclude a plate configured such that, when the distal projection isseated in a bone hole, the plate lies over a surface of the bonestructure in which the bone hole is formed. The chamber can extend intothe plate. The plate can include at least one opening through which abone anchor can be received to anchor the plate to bone disposedadjacent thereto.

In some embodiments, a thermal device includes a bone plate having achamber defined therein; a delivery conduit extending from the boneplate, the delivery conduit being configured to supply a thermal mediumto the chamber; and an exhaust conduit extending from the bone plate,the exhaust conduit being configured to withdraw the thermal medium fromthe chamber.

In some embodiments, a thermal device includes a bone plate having abone-contacting surface and at least one opening formed thereinconfigured to receive a bone anchor for anchoring the bone plate tobone; and at least one bone anchor having delivery and exhaust conduitsextending therefrom configured to circulate a cooled or heated fluidthrough the first bone anchor. The plate can include a chamber formedtherein and delivery and exhaust conduits extending from the plateconfigured to circulate a cooled or heated fluid through the chamber.The plate can be rigid.

In some embodiments, a method of applying localized thermal therapyincludes forming a bone hole in a bone structure of a patient; seating anon-threaded cylindrical distal projection of a bone plug in the bonehole; and delivering a thermal medium through a delivery conduit to achamber formed in the bone plug to apply a thermal effect to the boneplug and apply localized thermal therapy to the bone structure andtissue adjacent thereto. The adjacent tissue can be or can includeneural tissue. The adjacent tissue can be or can include a spinal canalof the patient. The method can include closing an incision through whichthe bone plug is inserted around the delivery conduit and applying thethermal effect after closing the incision. The method can includeremoving the bone plug from the bone hole by pulling the deliveryconduit proximally through the closed incision and pulling the deliveryconduit and the bone plug out of the patient through the closedincision. The method can include decoupling the delivery conduit fromthe bone plug by pulling the delivery conduit proximally through theclosed incision and pulling the delivery conduit out of the patientthrough the closed incision.

In some embodiments, a method of applying localized thermal therapy,includes positioning a bone plate adjacent to at least one bonestructure of a patient; securing the bone plate to the at least one bonestructure using one or more bone anchors; delivering a thermal mediumthrough a delivery conduit to a chamber formed in at least one of thebone plate and the one or more bone anchors, thereby applying a thermaleffect to the bone plate and applying localized thermal therapy to theat least one bone structure and tissue adjacent thereto. The method caninclude closing an incision around the delivery conduit. The method caninclude selectively decoupling the delivery conduit from the bone plateor the bone anchors and removing the delivery conduit through the closedincision.

In some embodiments, a thermal device includes a first clamping armhaving a first cavity, a first delivery conduit configured to supply athermal medium to the first cavity, and a first exhaust conduitconfigured to withdraw the thermal medium from the first cavity; asecond clamping arm pivotally coupled to the first clamping arm, thesecond clamping arm having a second cavity, a second delivery conduitconfigured to supply a thermal medium to the second cavity, and a secondexhaust conduit configured to withdraw the thermal medium from thesecond cavity;

the first and second clamping arms each having an engagement portionconfigured to grasp an implant or an anatomical structure, theengagement portions forming a substantial negative of the implant or theanatomical structure. The first cavity can be formed entirely in adistal portion of the first clamping arm adjacent the engagement portionof the first clamping arm, the first cavity being in fluid communicationwith the first delivery conduit and the first exhaust conduit via fluidpathways having a reduced cross-section that extend through the firstclamping arm; and

the second cavity can be formed entirely in a distal portion of thesecond clamping arm adjacent the engagement portion of the secondclamping arm, the second cavity being in fluid communication with thesecond delivery conduit and the second exhaust conduit via fluidpathways having a reduced cross-section that extend through the secondclamping arm.

In some embodiments, a method of applying localized thermal therapy,includes forming an incision in a patient; inserting at least a portionof a clamp through the incision; grasping an implant implanted in apatient or an anatomical structure of the patient with first and secondopposed arms of the clamp; and delivering a thermal medium through afirst delivery conduit to a first chamber formed in the first arm of theclamp and delivering a thermal medium through a second delivery conduitto a second chamber formed in the second arm of the clamp to apply athermal effect to the clamp and thereby apply localized thermal therapyto the implant or anatomical structure. The method can include closingthe incision around the first and second delivery conduits such that thedelivery conduits extend through the closed incision while the clampremains implanted in the patient. The method can include decoupling thefirst and second delivery conduits from the clamp after closing theincision and removing the delivery conduit through the closed incision.

In some embodiments, a thermal therapy system includes a disc implantsized and configured for placement between superior and inferiorvertebrae, the implant having a superior bone contacting surface, aninferior bone contacting surface, a first side surface configured toface a spinal canal when the implant is disposed between superior andinferior vertebrae, a second side surface opposite to the first sidesurface, and third and fourth side surfaces extending between the firstand second side surfaces; a thermally-conductive member coupled to theimplant and configured to extend across at least one surface of theimplant; and a thermal probe having a chamber formed therein to which athermal medium can be delivered to apply a thermal effect to the thermalprobe; wherein the thermal probe can be coupled to or placed in contactwith the thermally-conductive member to apply the thermal effect to thethermally-conductive member and tissue proximate thereto. Thethermally-conductive member can be or can include a plate coupled to thefirst side surface of the implant. The thermally-conductive member canbe a load bearing component of the implant configured to bearphysiological loads. The implant can be sized and configured fordelivery to a disc space via a lateral approach. The implant can besized and configured for delivery to a disc space via an anteriorapproach. The implant can be sized and configured for delivery to a discspace via a posterior approach. The thermally-conductive member caninclude a first plate coupled to the first side surface of the implantand a second plate coupled to the second side surface of the implant.The thermally-conductive member can include a first thin layer ofthermally-conductive material applied to the first side surface of theimplant and a second thin layer of thermally-conductive material appliedto the second side surface of the implant. The thermally-conductivemember can include a C-shaped plate configured to extend across thefirst side surface and the third and fourth side surfaces of theimplant. First and second terminal ends of the plate can sit flush withthe second side surface of the implant. The thermally-conductive membercan include an O-shaped plate configured to extend across the first sidesurface, the second side surface, and the third and fourth side surfacesof the implant.

In some embodiments, a method of applying localized thermal therapyincludes forming an incision in a patient; inserting at least a portionof a thermal probe through the incision; at least one of coupling thethermal probe to a disc implant disposed within a disc space of apatient and placing the thermal probe in contact with the disc implant;applying a thermal effect to the thermal probe, thereby applying athermal effect to the disc implant and applying localized thermaltherapy to tissue proximate to the disc implant. Applying a thermaleffect to the thermal probe can include delivering a thermal medium to achamber formed in the thermal probe. The method can include closing theincision around the thermal probe such that the thermal probe extendsthrough the closed incision while remaining in contact with or coupledto the implant. The method can include decoupling the thermal probe fromthe implant after closing the incision and removing the thermal probethrough the closed incision.

In some embodiments, a thermal therapy device includes a pad having anupper surface, a lower surface, and a sidewall extending therebetween,the pad defining a chamber therein; a fluid inlet conduit extending fromthe pad and in fluid communication with the chamber; a fluid outletconduit extending from the pad and in fluid communication with thechamber; a thermal source coupled to the fluid inlet conduit and thefluid outlet conduit and configured to circulate heated or chilled fluidthrough a fluid path defined by the fluid inlet conduit, the chamber,and the fluid outlet conduit to apply thermal therapy to anatomydisposed in proximity to the pad. The upper surface of the pad caninclude one or more grooves or enclosed loops for retaining sutures. Thepad can include at least one opening through which fluid can drip fromthe chamber into surrounding tissue. The at least one opening caninclude a plurality of openings formed in a grid pattern in the lowersurface of the pad. The at least one opening can be formed in adistal-facing portion of the sidewall of the pad. The pad can include atleast one suction port through which fluid can be evacuated from thevicinity of the pad through an aspiration conduit. The at least onesuction port can be formed in a proximal end of the pad, adjacent to alocation at which the inlet and outlet conduits meet the pad. The atleast one suction port can be formed in a distal-facing potion of thesidewall of the pad. The pad can include at least one wing extendingoutward therefrom configured to increase contact area with anatomy of apatient when the pad is placed in contact with said anatomy for at leastone of stabilization and adhesion. The pad can include upper and lowerrigid shells that define the chamber therebetween. The lower shell canbe formed from a thermally-conductive material and the upper shell canbe formed from a thermally-insulative material.

In some embodiments, a surgical method includes forming an incision in apatient; inserting a pad through the incision and positioning the pad ata target site within the patient; closing the incision around anaspiration conduit extending proximally from the pad with the pad at thetarget site; and after closing the incision, aspirating fluid throughthe aspiration conduit.

In some embodiments, a method of applying localized thermal therapyincludes forming an incision in a patient; inserting a pad through theincision and positioning the pad at a target site within the patient;closing the incision around at least one fluid outlet conduit extendingproximally from the pad with the pad at the target site; and afterclosing the incision, delivering a heated or cooled fluid through the atleast one fluid conduit to a chamber formed in the pad and releasing atleast a portion of the fluid into the target site through one or moreopenings formed in the pad. The at least one fluid conduit can includean aspiration conduit and the method can include aspirating fluid fromthe target site through the aspiration conduit. The method can includeaspirating fluid from the target site while simultaneously deliveringheated or cooled fluid to the pad. Positioning the pad can includepositioning the pad under a lamina of the patient. The method caninclude at least temporarily adhering at least a portion of the pad to aspinal canal of the patient.

In some embodiments, a thermal therapy device can include a length offlexible tubing having first and second free ends, the length of tubingbeing bent into a predetermined non-linear shape;

a biodegradable or bioabsorbable substrate coupled to the tubing andconfigured to maintain the tubing in the non-linear shape until thesubstrate is at least partially dissolved; a thermal source coupled toat least one of the free ends of the tubing and configured to circulateheated or chilled fluid through a fluid path defined by the tubing toapply thermal therapy to anatomy disposed in proximity to the tubing.The length of tubing can have an outside diameter that is less thanabout 5 mm. The substrate can be or can include a planar sheet to whichthe tubing is adhered. The tubing can be encapsulated in the substrate.The first and second free ends can be coupled to the thermal source. Thelength of tubing can include a first interior lumen and a secondinterior lumen. The first free end can be coupled to the thermal sourceand the second free end of the tubing can be closed, a fluidcommunication path between the first and second lumens being definedadjacent the second free end.

In some embodiments, a method of applying localized thermal therapyincludes forming an incision in a patient; inserting a length offlexible tubing through the incision and positioning a bent portion ofthe tubing at a target site within the patient, the bent portion of thetubing being formed into a predetermined non-linear shape and maintainedin said shape by a biodegradable substrate coupled to the tubing;closing the incision around an unbent portion of the tubing that extendsproximally from the bent portion with the bent portion being positionedat the target site; and after closing the incision, delivering a heatedor cooled fluid through the length of tubing to apply localized thermaltherapy to tissue in proximity to the bent portion of the tubing. Themethod can include pulling the length of tubing out of the patientthrough the closed incision by transitioning the bent portion of thetubing to an unbent configuration after the substrate dissolves in thepatient. The unbent portion can include first and second free ends ofthe length of tubing. The unbent portion can include a first free end ofthe tubing and the bent portion of the tubing can include a second freeend of the tubing. Delivering the fluid can include delivering the fluidinto a first inner lumen of the tubing such that the fluid flows throughthe first inner lumen and then enters a second inner lumen in fluidcommunication with the first inner lumen adjacent the second free end ofthe tubing.

The present invention further provides methods, systems, and devices asclaimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be more fully understood from the following detaileddescription taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 is a schematic view of a system for applying thermal therapy;

FIG. 2A is a profile view of a bone anchor insert thermal deviceinserted in a bone anchor;

FIG. 2B is a sectional perspective view of the thermal device of FIG.2A;

FIG. 2C is a sectional profile view of the thermal device and bone screwof FIG. 2A;

FIG. 3A is a sectional profile view of a bone anchor insert thermaldevice inserted in a bone anchor with a capped cannulation;

FIG. 3B is a sectional profile view of the thermal device of FIG. 3Ainserted in a bone anchor with an incomplete cannulation;

FIG. 3C is a sectional profile view of the thermal device of FIG. 3Ainserted in a bone anchor with a complete cannulation;

FIG. 4A is a profile view of a bone anchor thermal device with a threadportion of the device shown in phantom;

FIG. 4B is a sectional profile view of the thermal device of FIG. 4A;

FIG. 4C is a sectional profile view of a bone anchor thermal device;

FIG. 5 is a sectional profile view of a guidewire thermal deviceinserted in a bone anchor;

FIG. 6A is an exploded profile view of a bone anchor thermal devicehaving a connector;

FIG. 6B is an exploded perspective view of the thermal device of FIG.6A;

FIG. 6C is a sectional profile view of the thermal device of FIG. 6A;

FIG. 6D is another sectional profile view of the thermal device of FIG.6A;

FIG. 6E is another sectional profile view of the thermal device of FIG.6A;

FIG. 6F is another sectional profile view of the thermal device of FIG.6A;

FIG. 6G is another sectional profile view of the thermal device of FIG.6A;

FIG. 6H is another sectional profile view of the thermal device of FIG.6A;

FIG. 6I is an exploded perspective view of a bone anchor thermal devicehaving a connector;

FIG. 6J is an exploded sectional perspective view of the thermal deviceof FIG. 6I;

FIG. 7A is a perspective view of a bone anchor thermal device;

FIG. 7B is a sectional perspective view of the thermal device of FIG.7A;

FIG. 7C is a sectional profile view of the thermal device of FIG. 7A;

FIG. 7D is a sectional perspective view of the thermal device of FIG. 7Awith an alternative plug design;

FIG. 8A is a perspective view of a bone anchor thermal device;

FIG. 8B is a profile view of the thermal device of FIG. 8A;

FIG. 9A is a sectional perspective view of a bone anchor insert thermaldevice inserted in a bone anchor;

FIG. 9B is a perspective view of the thermal device and bone anchor ofFIG. 9A;

FIG. 10A is a sectional perspective view of a bone anchor insert thermaldevice inserted in a bone anchor with a spinal rod;

FIG. 10B is a perspective view of the thermal device, bone anchor, andspinal rod of FIG. 10A;

FIG. 11A is a sectional perspective view of a bone anchor insert thermaldevice inserted in a bone anchor;

FIG. 11B is a perspective view of the thermal device and bone anchor ofFIG. 11A;

FIG. 12A is a perspective view of a bone anchor insert thermal deviceinserted in a bone anchor;

FIG. 12B is a perspective view of the thermal device of FIG. 12A;

FIG. 12C is a sectional profile view of the thermal device of FIG. 12A;

FIG. 12D is a perspective view of a bone anchor insert thermal device;

FIG. 12E is an exploded perspective view of the thermal device of FIG.12D;

FIG. 12F is a sectional profile view of the thermal device of FIG. 12D;

FIG. 13A is a sectional profile view of a bone anchor extension thermaldevice;

FIG. 13B is a sectional profile view of the thermal device of FIG. 13Acoupled to a bone anchor;

FIG. 13C is a perspective view of the thermal device of FIG. 13A coupledto a bone anchor;

FIG. 13D is a perspective view of a bone anchor extension thermaldevice;

FIG. 14A is a perspective view of a cross-connector thermal devicecoupled to first and second spinal rods;

FIG. 14B is a sectional profile view of the thermal device of FIG. 14Ashown adjacent to a spinal canal;

FIG. 15 is a perspective view of a cross-connector thermal devicecoupled to first and second spinal rods;

FIG. 16A is a perspective view of a spinous process thermal device;

FIG. 16B is a sectional perspective view of the thermal device of FIG.16A;

FIG. 16C is a plan view of the thermal device of FIG. 16A and first andsecond spinous processes;

FIG. 16D is a profile view of the thermal device of FIG. 16A, first andsecond spinous processes, and a spinal canal;

FIG. 17A is a perspective view of a spinous process thermal device;

FIG. 17B is a sectional perspective view of the thermal device of FIG.17A;

FIG. 17C is a plan view of the thermal device of FIG. 17A, first andsecond spinous processes, and a spinal canal;

FIG. 17D is a profile view of the thermal device of FIG. 17A and firstand second spinous processes;

FIG. 18A is a sectional perspective view of a spinous process thermaldevice and first and second spinous processes;

FIG. 18B is another sectional perspective view of the thermal device ofFIG. 18A;

FIG. 18C is a perspective view of the thermal device of FIG. 18A andfirst and second spinous processes;

FIG. 19A is a sectional perspective view of a spinous process thermaldevice;

FIG. 19B is another sectional perspective view of the thermal device ofFIG. 19A;

FIG. 19C is a perspective view of the thermal device of FIG. 19A;

FIG. 20A is a perspective view of a spinal canal shield thermal device;

FIG. 20B is a plan view of the thermal device of FIG. 20A;

FIG. 20C is a profile view of the thermal device of FIG. 20A;

FIG. 20D is a perspective view of a spinal canal shield thermal device;

FIG. 20E is a plan view of the thermal device of FIG. 20D;

FIG. 21A is a perspective view of a spinous process device;

FIG. 21B is a plan view of the device of FIG. 21A;

FIG. 21C is a profile view of the device of FIG. 21A;

FIG. 22A is a perspective view of a spinal rod thermal device;

FIG. 22B is a sectional profile view of a barbed coupling and thethermal device of FIG. 22A;

FIG. 22C is a sectional profile view of a tapered fitting and thethermal device of FIG. 22A;

FIG. 23A is a profile view of a spinal rod thermal device coupled to abone anchor outrigger;

FIG. 23B is a perspective view of the thermal device of FIG. 23A coupledto a plurality of bone anchor outriggers;

FIG. 24 is a perspective view of a probe thermal device;

FIG. 25 is a perspective view of a drill or tap thermal device;

FIG. 26A is a perspective view of a bone plug thermal device;

FIG. 26B is a sectional profile view of the thermal device of FIG. 26A;

FIG. 27A is a perspective view of a bone plug and plate thermal device;

FIG. 27B is a sectional profile view of the thermal device of FIG. 27A;

FIG. 28A is a perspective view of a bone plug and plate with boneanchors thermal device;

FIG. 28B is a sectional profile view of the thermal device of FIG. 28A;

FIG. 29A is a perspective view of a bone plate thermal device;

FIG. 29B is a sectional profile view of the thermal device of FIG. 29A;

FIG. 30A is a perspective view of a bone plate with bone anchor thermaldevices;

FIG. 30B is a sectional profile view of the thermal device of FIG. 30A;

FIG. 31A is a perspective view of a clamp thermal device;

FIG. 31B is a sectional profile view of the thermal device of FIG. 31A;

FIG. 31C is a sectional profile view of a clamp thermal device;

FIG. 32A is a perspective view of an interbody thermal device;

FIG. 32B is a plan view of the thermal device of FIG. 32A;

FIG. 32C is an exploded plan view of the thermal device of FIG. 32A;

FIG. 33A is a perspective view of an interbody thermal device;

FIG. 33B is a profile view of the thermal device of FIG. 33A;

FIG. 34A is an exploded plan view of an interbody thermal device;

FIG. 34B is a plan view of the thermal device of FIG. 34A;

FIG. 34C is a profile view of the thermal device of FIG. 34A;

FIG. 35A is a perspective view of an interbody thermal device;

FIG. 35B is a plan view of the thermal device of FIG. 35A;

FIG. 35C is an exploded plan view of the thermal device of FIG. 35A;

FIG. 36A is a perspective view of an interbody thermal device;

FIG. 36B is a profile view of the thermal device of FIG. 36A;

FIG. 36C is a profile view of the thermal device of FIG. 36A;

FIG. 36D is a profile view of the thermal device of FIG. 36A;

FIG. 36E is a profile view of the thermal device of FIG. 36A;

FIG. 37A is a perspective view of an interbody thermal device;

FIG. 37B is an exploded plan view of the thermal device of FIG. 37A;

FIG. 37C is a plan view of the thermal device of FIG. 37A;

FIG. 38A is a perspective view of an interbody thermal device;

FIG. 38B is a plan view of the thermal device of FIG. 38A;

FIG. 38C is an exploded plan view of the thermal device of FIG. 38A;

FIG. 39A is a perspective view of a pad thermal device;

FIG. 39B is a sectional profile view of the thermal device of FIG. 39A;

FIG. 39C is a profile view of the thermal device of FIG. 39A;

FIG. 39D is a perspective view of a pad thermal device;

FIG. 39E is a perspective view of a pad thermal device;

FIG. 39F is a perspective view of a pad thermal device;

FIG. 39G is a perspective view of a pad thermal device;

FIG. 39H is a perspective view of a pad thermal device;

FIG. 39I is a perspective view of a pad thermal device;

FIG. 39J is a perspective view of a pad thermal device;

FIG. 39K is a sectional perspective view of the thermal device of FIG.39J;

FIG. 39L is a perspective view of a pad thermal device;

FIG. 39M is a sectional perspective view of the thermal device of FIG.39L;

FIG. 39N is a perspective view of a pad thermal device;

FIG. 39O is a sectional perspective view of the thermal device of FIG.39N;

FIG. 40A is a perspective view of a tubing thermal device;

FIG. 40B is a perspective view of the thermal device of FIG. 40A with asubstrate removed;

FIG. 40C is a sectional plan view of the thermal device of FIG. 40A;

FIG. 41A is a perspective view of a tubing thermal device;

FIG. 41B is a perspective view of the thermal device of FIG. 41A with asubstrate removed;

FIG. 41C is a sectional plan view of the thermal device of FIG. 40A;

FIG. 42 is a flowchart of an exemplary method of applying thermaltherapy; and

FIG. 43 is a flowchart of an exemplary method of applying thermaltherapy.

DETAILED DESCRIPTION

Methods and devices are disclosed herein that generally involve applyingthermal therapy to tissue (e.g., localized cooling or heating oftissue), and in particular applying thermal therapy to the spinal canal,tissue disposed within the spinal canal, and/or nerve roots extendingfrom the spinal canal. In some embodiments, tissue can be cooled orheated by implanting or positioning a thermal device in proximity to thetargeted tissue. A number of exemplary thermal devices are disclosed,including bone anchors, inserts for use with bone anchors, K-wires, boneanchor extensions or towers, cross-connectors, spinous process plates,spinal rods, pedicle markers, bone taps, drill bits, bone plugs, boneplates, clamps, interbody or disc implants, thermal pads, and tubingloops. The thermal device can be left in place following surgery tofacilitate application of post-surgical thermal therapy. In someembodiments, the thermal device can be removed post-surgery in aminimally- or non-invasive manner.

Certain exemplary embodiments will now be described to provide anoverall understanding of the principles of the structure, function,manufacture, and use of the methods and devices disclosed herein. One ormore examples of these embodiments are illustrated in the accompanyingdrawings. Those skilled in the art will understand that the methods anddevices specifically described herein and illustrated in theaccompanying drawings are non-limiting exemplary embodiments and thatthe scope of the present invention is defined solely by the claims. Thefeatures illustrated or described in connection with one exemplaryembodiment can be combined with the features of other embodiments. Suchmodifications and variations are intended to be included within thescope of the present invention.

In the description that follows, reference is made primarily to treatingtissue in and around the spinal canal, including the spinal cord, but itwill be appreciated that the methods and devices disclosed herein canalso be used to treat tissue in virtually any part of a human or animalbody, including organs, joints (e.g., hips, knees, elbows, shoulders),the brain, the heart, etc. It will also be appreciated that the term“spinal tissue” as used herein can include the spinal cord itself, aswell as nerves and nerve roots extending therefrom through spaces in thespinal column, together the “spinal neuraxis,” as well as other portionsof the central nervous system.

Furthermore, while methods and devices for cooling tissue are primarilydisclosed herein, it will be appreciated that the same or similarmethods and devices can be used to heat tissue, e.g., for the purpose ofapplying localized therapeutic hyperthermia.

In some embodiments, methods of applying thermal therapy involve“implanting” a thermal device in the patient. As used herein,“implanting” the thermal device refers to leaving at least a portion ofthe thermal device in the patient after the initial surgical phase oftreatment is completed (e.g., by closing a tissue opening over theimplanted device while tubing or connectors associated therewith extendthrough the closed incision). Implanting the thermal device facilitatesdelivery of postoperative thermal therapy, optionally for an extendedtime period or in multiple sessions over a prolonged period, which canprovide unexpected benefits for the patient.

For example, peak edema typically does not subside until about three tofive days after a spinal cord injury is sustained. With an implantablesystem, therapeutic hypothermia can be delivered throughout this periodto minimize swelling-related damage to the patient's spinal cord. Theability to implant the thermal device also allows for the patient to beclosed immediately following decompression, stabilization, or othersurgery that may be performed in connection with implanting the device,yet still preserves the ability to apply thermal therapy for extendedtime periods. It is desirable to conclude the initial surgical phase oftreatment as soon as possible so as to reduce the patient's exposure topossible infection, reduce the amount of time the patient must be underanesthesia, reduce the cost of the surgery by reducing the amount oftime required of surgeons, operating staff, operating rooms, and otherresources, improve hospital throughput by freeing up resources to treatother patients, and so forth.

The thermal device can be left implanted for any amount of time (e.g.,at least about 1 hour, at least about 4 hours, at least about 12 hours,at least about 18 hours, at least about 24 hours, at least about 48hours, at least about 72 hours, at least about 5 days, at least about 7days, at least about 2 weeks, at least about 1 month, at least about 3months, at least about 6 months, at least about 1 year, at least about 5years, at least about 10 years, and/or permanently or indefinitely).

System

FIG. 1 illustrates an exemplary embodiment of a system 100 for applyingthermal therapy. The system 100 generally includes a thermal device 102and a source 104 configured to provide a cooling or heating means to thedevice 102. Delivery of the cooling or heating means can be regulated bya controller 106. The thermal device 102 can include one or more boneanchors, inserts for use with bone anchors, K-wires, bone anchorextensions or towers, cross-connectors, spinous process plates, spinalrods, pedicle markers, bone taps, drill bits, bone plugs, bone plates,clamps, interbody or disc implants, thermal pads, tubing loops,containers, pouches, balloons, sacs, etc. that can be positioned inproximity to tissue that is to be cooled or heated. A number ofexemplary thermal devices 102 are described in detail below. The thermaldevice 102 can be placed in direct contact with the tissue to be cooledor heated, or can apply a cooling or heating effect to the tissue in anindirect manner, e.g., through intermediate tissue, implants, or otherstructures.

Exemplary tissue that can be cooled or heated using the thermal device102 includes the spinous process, the vertebral body, the pedicles, thelaminae, the spinal canal, the spinal canal contents (including thespinal cord), nerves (including those surrounding or extending to/fromthe spinal cord), vessels, and muscles. The spinal canal contentsinclude, for example, epidural space, dura mater, subdural space,arachnoid space, subarachnoid space, intrathecal space, cerebral spinalfluid, pia mater, spinal arteries and veins, vasocorona, vertebralvenous plexus, nerve roots, ligaments, and fatty tissue. It will beappreciated that there is symmetry as well as repetitive elements to avertebra and referral to an element of the vertebra can be taken to meanany one of symmetric or multiple elements. For example, when referringto a pedicle, it can be intended to mean any one of the two, or both,pedicles of the vertebra.

Cooling/Heating Means and Source

The thermal device 102 can provide a cooling or heating effect using anyof a number of different cooling or heating means or combinationsthereof. For example, the cooling means can include the expansion of gaswithin the thermal device 102 or the circulating of a chilled fluidthrough the thermal device 102. The term “fluid,” as used herein, refersto any flowable material or collection of materials, including liquids,gases, and combinations thereof. In some embodiments, the thermal device102 receives a compressed gas which by expansion acts as a coolant inthe thermal device 102. The expansion of the gas causes the gas and thethermal device 102 around it to experience a rapid decrease intemperature. Typical gases for such an application include Nitrous Oxideand Carbon Dioxide, but it will be appreciated that there are a widevariety of gases that can be used, including gases which, in compressedform, will be liquid.

In other embodiments, the thermal device 102 receives a chilled liquidas the cooling means which flows through cavities or channels of thethermal device, thereby decreasing the temperature of the thermaldevice. Typical chilled liquids include saline solutions, water, liquidnitrogen, and ethyl alcohol. It will be appreciated that any number offluids can be used as the cooling means, and that there are advantagesto using biologically safe fluids. In still other embodiments, thethermal device 102 can include a thermoelectric device, such as aPeltier device, which when a voltage or current is applied, at least aportion of the device experiences a reduction in temperature. Thethermal device 102 can also house an endothermic chemical reaction whichresults in the reduction of temperature of the contents of the thermaldevice 102 and of the thermal device 102 itself. In other embodiments,the thermal device 102 is pre-chilled prior to a cooling procedure. Itwill be appreciated by those skilled in the art that there are a varietyof means by which the thermal device 102 can be cooled.

In embodiments in which the thermal device 102 is used to apply heat, aheated fluid or gas can be circulated through the device, the device caninclude an electric heating element (e.g., a resistive heating element),the device can be pre-heated, the device can house an exothermicreaction, etc.

The thermal source 104 can be external (e.g., extracorporeal), can beimplanted in the patient, and/or can be formed integrally with thethermal device 102. In implementations in which the cooling means is anexpanding gas, the thermal source 104 can be a tank of compressed gaswhich is released into the thermal device 102 through a cooling deliveryconduit. Once the compressed gas is in the thermal device 102, it can beexpanded through an expansion nozzle into an expansion chamber in thethermal device 102, causing a rapid decrease in temperature.Alternatively, or in addition, the thermal source 104 can include acompressor that compresses the gas. In some implementations, thedelivery of the cooling means from the tank of compressed gas isregulated with the control unit 106 to limit the amount of gas and thepressure at which it enters the thermal device 102 via the coolingdelivery conduit. The control unit 106 can be an adjustable valve on thetank, which can be manually controlled, mechanically controlled, orautomatically controlled by a computing device. In implementations inwhich the thermal source 104 includes a compressor, the control unit 106can control the degree to which the compressor compresses the gas, orthe pressure of the gas presented down the conduit. The regulation ofthe release of the gas can be managed manually or automatically, ineither case, based on established protocols, conditions of the patient,and/or detectable physiological characteristics of the patient orcharacteristics of the thermal device.

An additional conduit can also be provided to exhaust expanded gas fromthe expansion chamber of the thermal device 102. The exhaust conduit canexhaust the gas into the atmosphere, to a collection tank, or to acompressor which in turn re-compresses the gas for reuse. As discussedfurther below, the delivery conduit and the exhaust conduit can begenerally circular in cross-section, and can be formed from any of avariety of medical-grade tubing materials known in the art. The conduitscan be flexible or rigid, or can include rigid portions and flexibleportions. Any of the conduits disclosed herein can be a multi-lumenconduit (e.g., one in which a first lumen is used to deliver a thermalmedium and a second lumen is used to extract or withdraw the thermalmedium). The lumens of a multi-lumen conduit can be coaxial (e.g., atube within a tube). The lumens of a multi-lumen conduit can also bearranged in other configurations. For example, multiple lumens can becoupled to one another such that they run in a parallel, side-by-sidearrangement. By way of further example, a conduit having a circularoutside cross-section can include one or more internal dividing walls todefine a multiple lumen internal cross-section (e.g., a double-Dcross-sectional configuration). Multi-lumen conduits can be formed usingany of a variety of techniques, including co-extrusion processes.

In implementations in which the cooling means is a chilled fluid, thethermal source 104 can be or can include a chiller or other apparatusfor cooling and pumping fluid, and the cooling delivery conduit can be atube for delivering the chilled fluid to the thermal device 102. In thiscase, the exhaust conduit can be used to return or exhaust the chilledfluid from the thermal device 102 back to the thermal source 104, to acollection tank, or to a drain. In such an implementation, the controlunit 106 can control the volume rate of chilled fluid flow, the pressureof the chilled fluid delivery lines, and/or the temperature of thechilled fluid. It will be appreciated that components of the fluiddelivery and circulation system can be positioned on the exhaust side ofthe system rather than the source side (e.g., a pumping mechanism thatpulls the chilled fluid through the device 102, the delivery conduit,and the exhaust conduit rather than pushing it through).

In implementations in which the cooling means is a Peltier deviceembedded in the thermal device 102, the thermal source 104 can include apower supply that powers the Peltier device, and the cooling deliveryconduit can include electrical lines that supply electrical current fromthe power supply to the Peltier device. The delivery and exhaustconduits can also be used to remove heat generated by the Peltier devicefrom the thermal device 102.

Delivery of the cooling means can be regulated to achieve apredetermined cooling effect, such as a specific temperature at aspecific location. Delivery of the cooling means can also be regulatedsuch that a specific volume of the cooling means is delivered, forexample in cases where the cooling means includes a chilled liquid orexpandable gas. Delivery of the cooling means can also be regulatedbased on changes or lack of changes in physiological characteristics.For example, the regulation of the cooling means, and thus the intensityof cooling, can be determined by quantitative and qualitative sensory ormotor-evoked potential (SEP, MEP) observations. In this example, thecooling means is provided at a certain level until the patient's SEP/MEPresults begin to degrade, improve, or otherwise change, at which pointthe regulation of the cooling means can begin to reduce or increase thedelivery of the cooling means.

It will be appreciated that any number of physiological characteristicscan be used to regulate the intensity of the cooling means, includingbut not limited to: blood pressure, target-tissue temperature, specifictissue temperature (proximate to target tissue), rectal bodytemperature, venous blood temperature near or exiting target tissue,pulmonary conditions, cardiac conditions, sensory evoked potentials(SEPs, including somatosensory evoked potentials), motor-evokedpotentials (MEPs), intrathecal pressure, perfusion pressure, levels ofblood oxygen & glucose, ATP concentrations, and effectors ofexcitotoxicity, vasogenic edema, apoptosis, inflammation, and enzymaticresponses. A real-time qualitative or quantitative determination can bemade based on any of the listed physiological characteristics as to howthe cooling means should be regulated.

One or more sensors can also be included in the thermal device 102and/or implanted in or around the patient. The sensor can be atemperature sensor embedded in or on the thermal device 102 to sense thetemperature the device exhibits, where this sensed temperature can thenbe used to control the delivery of the cooling means to the thermaldevice 102. The sensor can be connected to the control unit 106 via oneor more sensor wires to provide a feedback loop of information to helpdetermine how much cooling means and/or what temperature cooling meansto deliver to the thermal device 102. Alternatively, or in addition, thesensor can be connected via sensor wires to a display, meter, dial, orother indicator providing some form of output data from the sensor thatcan allow one to manually regulate the delivery of the cooling means.The sensor can also be connectable wirelessly and a wireless link can beused instead of the sensor wires.

In one implementation, a first sensor is embedded into the thermaldevice 102 and provides temperature data of the thermal device 102 and asecond sensor is implanted in the intrathecal space of the spinal canalto measure temperature of cerebral spinal fluid. This temperature datacan be used to either manually or automatically regulate the delivery ofthe cooling means.

It will be appreciated that more than one sensor, more than one sensortype, and more than one sensor placement location can be usedsimultaneously and that the data gathered from the multiple sensors canbe used independently or in combination to determine how the delivery ofthe cooling means is regulated. Exemplary sensors that can be usedinclude temperature sensors (e.g., thermistors or thermocouples),pressure sensors, chemical sensors, electrical sensors, magneticsensors, and optical sensors. Other types of sensing, such as remotesensing, can be used that do not require the sensor itself to be placedwithin the patient—ultrasound, including Doppler measurements, andfunctional MRI, all can be used to sense physiological characteristicsthat can be used to control or regulate the delivery of the coolingmeans. The information measured by a sensor or sensors can be used tocontinually adjust the regulation of the delivery of the cooling meansin real time or almost real time. Alternatively, or in addition, thesensed information can be used for safety monitoring. The advantages ofusing a sensor or sensors, along with sensor wires or othercommunication means, will be appreciated though their use may not benecessary.

Thermal Devices

A number of exemplary thermal devices are described below. Any of thesethermal devices can be used with the system described above and caninclude any of the features described above. In addition, the variousfeatures of the thermal device described below can be readilyinterchanged or combined with one another, and the specific arrangementsshown and described are merely exemplary.

Bone Anchor Thermal Devices

FIGS. 2A-2C illustrate an exemplary thermal device 202. The device 202includes a plug or insert 204 that can be inserted into a standardcannulated bone anchor (e.g., a bone screw 206). The plug 204 caninclude first and second concentric tubes 208, 210 configured to bepositioned in the cannulation of the bone screw to define inner andouter chambers. The distal end of the inner tube 208 can be open suchthat fluid can exit the distal end of the inner tube and flow into theouter tube 210 adjacent a distal end thereof. The distal end of theouter tube 210 can be closed such that fluid entering the outer tubeadjacent a distal end thereof must flow back along the length of theouter tube towards a proximal end of the outer tube. Cooled or heatedfluid can be directed through an inlet conduit and through the innerchamber defined by the inner tube 208. The fluid can exit the distal endof the inner tube 208 and flow back along the outer chamber defined bythe outer tube 210 and into an outlet conduit. The inlet conduit can beconcentric with the outlet conduit over a portion of its length, and canthen exit a sidewall of the outlet conduit at a location proximal to thebone screw 206. In some embodiments, fluid can flow in the oppositedirection through the device 202. In use, the thermal device 202 can beinserted into the cannulation of a bone anchor placed using standardtechniques, and a cooled or heated medium can be directed through thedevice to heat or cool the bone anchor and apply localized thermaltherapy to target anatomy in proximity thereto.

FIG. 3A illustrates an exemplary thermal device 302. The thermal device302 is similar to the thermal device 202, except that the outer tube isomitted and the outer chamber is instead defined by the screwcannulation. A cap 312 can be positioned within a distal end of thecannulation of the screw 306 to seal the distal end. A plug or insert304 can be inserted into the proximal end of the screw. While not shown,it will be appreciated that the plug 304 can be inserted into thecannulation of the bone anchor or a recess formed proximal to thecannulation to form a fluid tight seal with the bone anchor. Cooled orheated fluid can be directed through a delivery conduit, through theplug 304, and through a tube 308 extending from the plug through thecannulation. The fluid can exit an open distal end of the tube 308 andflow back along the cannulation of the screw 306 to the plug 304 andinto an exhaust conduit 310. The delivery conduit can be concentric withthe exhaust conduit over a portion of its length, and can then exit asidewall of the exhaust conduit at a location proximal to the plug 304.In some embodiments, fluid can flow in the opposite direction throughthe device 302. In use, the thermal device 302 can be inserted into thecannulation of a bone anchor placed using standard techniques, and acooled or heated medium can be directed through the device and the boneanchor to cool or heat the bone anchor and apply localized thermaltherapy to target anatomy in proximity thereto.

As shown in FIG. 3B, the thermal device 302 can be used with a partiallycannulated bone anchor 306′ (e.g., a bone anchor in which thecannulation does not extend through the distal end of the anchor suchthat the distal end of the anchor is closed). In such instances, the cap312 can be omitted. As shown in FIG. 3C, the patient's anatomy (e.g.,the end of a blind bore 314 formed in a bony structure of a patient'sspine) can be used to seal the distal end of a fully-cannulated boneanchor 306″ instead of or in addition to the cap 312.

FIGS. 4A-4C illustrate an exemplary thermal device 402. The thermaldevice 402 can be generally in the form of a bone anchor having athreaded distal portion 404 and an enlarged head portion (not shown).The bone anchor can include any of a variety of known features,including a head portion that defines a recess in which a spinalfixation element such as a spinal rod can be received. A fluid flowconduit 406 can be defined within the threads 408 of the bone anchor(e.g., entirely within the threads of the bone anchor). In use, cooledor heated fluid can be directed through the conduit 406 to apply athermal effect (e.g., heating or cooling) to the screw and/or tosurrounding tissue. In some embodiments, the conduit 406 can be wrappedaround the screw shaft independent from the threads 408. The device 402can include a single-lumen conduit 406 in the thread as shown in FIG.4B, or can include a multi-lumen conduit 406′ having delivery andexhaust lumens 410, 412 as shown in FIG. 4C. In the embodiment of FIG.4B, fluid delivered through the single-lumen conduit 406 can be returnedthrough an exhaust conduit (not shown) that extends through a centralportion of the bone screw. The helical pattern of the thermal conduitcan advantageously deliver a more uniform thermal effect across thelength and circumference of the bone anchor.

FIG. 5 illustrates an exemplary thermal device 502. The thermal device502 can include a thermal clamp 504 configured to clamp onto a proximalportion of a standard guidewire, K-wire, or other elongate structure 506inserted through the cannulation of a standard bone anchor 508. Thethermal clamp 504 can include a chamber or conduit formed thereinthrough which a heated or cooled fluid can be circulated to heat or coolthe K-wire 506, the bone anchor 508, and/or surrounding tissue. TheK-wire 506 can be formed from a thermally conductive material tofacilitate transfer of the heating or cooling effect to the bone anchor508. In some embodiments, a portion of the K-wire 506 intermediate to adistal portion that sits within the cannulation of the bone anchor 508and a proximal portion that is grasped by the clamp 504 can be coatedwith a thermally-insulating material to reduce the delivery of thethermal effect to non-targeted tissue.

FIGS. 6A-6H illustrate an exemplary thermal device 602. The thermaldevice generally includes a bone anchor 604 (e.g., a bone screw) and aconduit connector 606 configured to be selectively coupled and/ordecoupled from the bone anchor.

The conduit connector 606 can be configured to couple elongate fluidinlet and outlet conduits 608, 610 to corresponding fluid lumens definedin or extending through the bone anchor 604. In the illustratedembodiment, the connector 606 include a body portion 612 having aproximal end from which the fluid inlet and outlet conduits 608, 610 canextend. The fluid inlet and outlet conduits 608, 610 can be formedintegrally with the connector 606, or can be coupled thereto using anyof a variety of techniques, including threaded engagement, snap-fitengagement, welding, gluing, etc. The body portion 612 can have fluidlumens 614, 616 defined therein to provide fluid communication betweenthe inlet and outlet conduits 608, 610 and the fluid lumens of the boneanchor 604. The connector 606 can also include one or more matingfeatures for selectively coupling the connector to the bone anchor. Forexample, the connector 606 can include first and second tabs 618extending distally from the body portion 612 configured to be receivedwithin corresponding first and second slots or channels 620 formed inthe bone anchor. The tabs 618 can be sized to form a slight interferencefit with the slots 620 in the bone anchor such that the connector issecurely coupled to the bone anchor until a sufficientproximally-directed force is applied to decouple the connector from thebone anchor. The connector 606 can also include male projections 622through which the fluid lumens of the connector extend configured to bereceived within corresponding female receptacles 624 of the bone anchor604 to establish a fluid-tight seal and provide fluid communicationbetween the connector and the bone anchor.

The bone anchor 604 can include a proximal tulip portion 626 thatdefines a U-shaped recess 628 in which a spinal fixation element (e.g.,a spinal rod) can be received. The U-shaped recess 628 can be defined byopposed arms 630. Inner and/or outer surfaces of the opposed arms 630can be threaded to receive a locking element (e.g., a set screw or alocking nut) to secure a spinal fixation element within the U-shapedrecess 628. The tulip portion 626 can include fluid inlet and outletlumens defined therein. For example, one or both of the opposed arms 630can include fluid inlet and/or outlet lumens.

The bone anchor 604 can also include a distal portion 632 configured tobe received within a bone opening. The distal portion 632 can include athreaded exterior surface configured to engage bone. The distal portion632 can also include a central cannulation 634 extending therethrough.The cannulation 634 can extend entirely through the distal portion ofthe bone anchor or only along a portion thereof. For example, a distalend of the cannulation 634 can be closed as shown in FIG. 6E.

The thermal device 602 can also include a plug or insert 636 seated in aproximal end of the cannulation 634. The plug 636 can be seated justbelow a female driving interface 638 of the bone anchor. The plug 636can include at least one tube 640 that extends distally therefrom intothe cannulation 634 of the bone anchor. The plug 636 can be securelymated to the bone anchor, for example using a threaded or snap fitinterface or by welding, gluing, etc. The plug 636 can include sealingfeatures to form a fluid-tight seal with the bone anchor when the plugis seated therein. For example, the plug can include one or more O-ringsor gaskets disposed about a circumference thereof configured to form aseal with an internal sidewall of the bone anchor.

When the thermal device 602 is assembled, as shown in FIGS. 6C-6H whichshow sectional views of the thermal device 602 in various planes, afluid loop can be defined through the thermal device. In particular,fluid can flow through an inlet conduit 608, through an inlet passage614 of the connector 606, through an inlet passage 642 of the tulip 626,through an inlet passage 644 of the plug 636, and through an inlet tube640 extending distally from the plug. The fluid can then enter thecannulation 634 of the bone anchor where it can encounter a cap disposedin the cannulation or a closed distal end of the cannulation, causingthe fluid to return proximally through the cannulation. The fluid canthen enter an outlet passage 646 of the plug and flow through an outletpassage 648 of the tulip 626, an outlet passage 616 of the connector606, and into an outlet conduit 610. In some embodiments, fluid can flowin the opposite direction through the device 602.

In use, heated or cooled fluid can be supplied through the inlet conduit608 and can flow through the thermal device 602 and back out through theoutlet conduit 610 to heat or cool the thermal device and surroundingtissue. When the thermal therapy is completed, or at any other desiredtime, the connector 606 can be de-coupled from the bone anchor 604(e.g., by applying a proximally-directed force of sufficient magnitude)and the connector and associated inlet/outlet conduits can be removedfrom the patient. The bone anchor 604 can be left in place and used aspart of a spinal fixation or stabilization construct. As described infurther detail below, the patient can be closed up with just the inletand outlet conduits 608, 610 extending through the closed incision, suchthat thermal therapy can be performed after the surgical procedure toimplant the thermal device 602. Later, the connector 606 and the fluidinlet and outlet conduits 608, 610 can be decoupled from the bone anchor604 in a non-surgical or minimally-invasive procedure by simply pullingthe conduits and the connector through the closed incision.

In the thermal device 602, the positioning of the fluid passages withinthe arms 630 of the tulip 626 can advantageously leave the U-shapedopening 628 in the tulip clear to receive a spinal fixation element.Accordingly, localized thermal therapy can be delivered via the thermaldevice 602 before, during, and/or after a spinal fixation element issecured to the bone anchor 604 without interfering with the installationof the spinal fixation element.

The illustrated device 602 uses a single tube 640 extending distallyfrom the plug 636 and a cannulation 634 of the bone anchor 604 to definea fluid path through the distal portion of the bone anchor. It will beappreciated, however, that other variations are also possible, includingany of those described above with respect to FIGS. 2A-3C.

In some embodiments, as shown in FIGS. 6I-6J, the thermal device 602 canbe configured such that the fluid path extends only through the tulipportion 626 of the bone anchor 604 and does not extend into the distalportion 632 of the bone anchor. In particular, the fluid path can bedefined such that fluid flows through the inlet conduit 608, through aninlet passage 614 in the connector, and through an inlet passage 642 inthe tulip (e.g., in one of the opposed arms 630 of the tulip), at whichpoint the fluid is then routed back to an outlet passage 648 in thetulip (e.g., in the same or a different arm 630 of the tulip), throughan outlet passage 616 in the connector, and through the outlet conduit610. Such an arrangement can advantageously provide for a simpler andless expensive thermal device 602 as compared with embodiments in whichthe fluid path extends through the distal portion of the bone anchor. Inaddition, the bone anchor can be a multi- or polyaxial bone anchor(e.g., a bone anchor in which the distal portion comprises a threadedshank and a head portion seated in a separate tulip component such thatan angle of the threaded shank with respect to the tulip can beadjusted).

FIGS. 7A-7D illustrate an exemplary thermal device 702. Except asindicated below, the structure and operation of the thermal device 702is substantially identical to the thermal device 602, and therefore adetailed description is omitted here for the sake of brevity. In thethermal device 702, a fluid inlet lumen can be formed in a first arm730A of the tulip portion 726 of the bone anchor 704 and a fluid outletlumen can be formed in a second, opposite arm 730B of the tulip portion.Accordingly, cooled or heated fluid can be directed through a fluid paththat extends through an inlet passage 742 of a first arm 730A of thetulip, an inlet passage 744 of the plug 736, and an inlet tube 740extending distally from the plug. The fluid can then enter a cannulation734 of the bone anchor 704 adjacent a distal end of the bone anchor,return along the cannulation, through an outlet passage 746 of the plug736, and through an outlet passage 748 of a second, opposite arm 730B ofthe tulip 726.

The fluid inlet and outlet passages formed in the opposed arms of thetulip can include openings formed in a proximal-facing surface of thetulip. Fluid inlet and outlet conduits can be coupled to said openings(e.g., via first and second connectors of the type described abovemodified to include only a single fluid passage in each connector).

As shown in FIG. 7D, the plug 736′ can optionally include features tofacilitate unforced convective flow of heated or cooled fluid throughthe device. For example, the center plug 736′ disposed in the tulip 726can include a tab or diverter 750 extending distally therefrom into achamber 752 defined in the base of the tulip. The tab 750 can be formedfrom one or more pieces, can extend in any of a variety of directions,and can have any of a variety of shapes or patterns. The tab 750 can beformed integrally with or can be attached, bonded, or coupled to thecenter plug 736′ as shown, or to any interior surface of the boneanchor. The tab 750 can extend into the cannulation 734 of the screwshaft. In some embodiments, the tab 750 can extend to the distal end ofthe cannulation of the screw shaft. In operation, fluid flows around thetab 750, which can direct the fluid flow and can create turbulence.

FIGS. 8A-8B illustrate an exemplary thermal device 802. Except asindicated below, the structure and operation of the thermal device 802is substantially identical to the thermal device 602, and therefore adetailed description is omitted here for the sake of brevity. In thethermal device 802, the connector 806 has a low-profile design. Theconnector 806 can include a distal-facing surface with male projectionsin which fluid passages are defined extending therefrom. The connector806 can be coupled to the tulip portion 826 of a bone anchor 804 suchthat the distal-facing surface of the connector abuts a proximal-facingsurface of the tulip portion and such that the male projections in whichthe fluid passages are defined are received within corresponding femalereceptacles formed in the tulip portion. The connector 806 can bepress-fit or otherwise coupled to the tulip portion 826 (e.g., at thetime of manufacture) and can subsequently be selectively decoupled fromthe tulip portion (e.g., by applying a proximally-directed force ofsufficient magnitude to separate the press-fit or other engagement).

FIGS. 9A-9B illustrate an exemplary thermal device 902. The device 902generally includes a bone anchor 904 (e.g., a bone screw) and a plug orinsert 906 configured to be selectively coupled and/or decoupled fromthe bone anchor.

The bone anchor 904 can include a proximal tulip portion 908 thatdefines a U-shaped recess 910 in which a spinal fixation element (e.g.,a spinal rod) can be received. The U-shaped recess 910 can be defined byopposed arms 912. Inner and/or outer surfaces of the opposed arms 912can be threaded to receive a locking element (e.g., a set screw or alocking nut) to secure a spinal fixation element within the U-shapedrecess 910. The tulip portion 908 can also include opposed cut-outs orreliefs 914 aligned with and formed beneath or distally to the U-shapedrecess 910.

The bone anchor 904 can also include a distal portion 916 configured tobe received within a bone opening. The distal portion 916 can include athreaded exterior surface configured to engage bone. The distal portion916 can also include a central cannulation 918 extending therethrough.The cannulation 918 can extend entirely through the distal portion ofthe bone anchor or only along a portion thereof. For example, a distalend of the cannulation can be closed.

The plug or insert 906 can be seated in a bore defined in a base portionof the tulip 908. The plug 906 can be seated in the bore in a flush orsub-flush manner such that the plug does not protrude proximally intothe U-shaped channel 910 defined by the tulip. The plug 906 can includeor can be coupled to fluid inlet and outlet conduits 920, 922 which canextend laterally outward from the plug. The inlet and outlet conduits920, 922 can be seated in the cut-outs or reliefs 914 formed in thetulip 908 when the plug 906 is seated in the bore. Accordingly, the plug906 and the fluid conduits 920, 922 can be installed in the bone anchor904 without interfering with placement or securement of a spinalfixation element (e.g., a spinal rod) within the U-shaped recess 910 ofthe bone anchor. The plug 906 can also include an inlet tube 924extending distally therefrom into the cannulation 918 of the boneanchor. The plug can be securely mated to the bone anchor, for exampleusing a threaded or snap fit interface or by welding, gluing, etc. Theplug can include sealing features to form a fluid-tight seal with thebone anchor when the plug is seated therein. For example, the plug caninclude one or more O-rings or gaskets disposed about a circumferencethereof configured to form a seal with an internal sidewall of the boneanchor.

When the thermal device 902 is assembled, a fluid loop can be definedthrough the thermal device. In particular, fluid can flow through theinlet conduit 920, through an inlet passage 926 of the plug 906, andthrough an inlet tube 924 extending distally from the plug. The fluidcan then enter the cannulation 918 of the bone anchor 904 where it canencounter a cap disposed in the cannulation or a closed distal end ofthe cannulation, causing the fluid to return proximally through thecannulation. The fluid can then enter an outlet passage 928 of the plugand flow through the outlet conduit 922. In some embodiments, fluid canflow in the opposite direction through the device 902.

In use, heated or cooled fluid can be supplied through the inlet conduit920 and can flow through the thermal device 902 and back out through theoutlet conduit 922 to heat or cool the thermal device and surroundingtissue. When the thermal therapy is completed, or at any other desiredtime, the conduits 920, 922 can be de-coupled from the plug 906 (e.g.,by applying a proximally-directed force of sufficient magnitude) andremoved from the patient. The bone anchor 904 and the plug 906 can beleft in place and used as part of a spinal fixation or stabilizationconstruct. In other words, the conduits can be separated from thethermal device 902 even after a spinal rod or other fixation element issecured within the U-shaped recess 910 of the bone anchor 904. Asdescribed in further detail below, the patient can be closed up withjust the inlet and outlet conduits 920, 922 extending through the closedincision, such that thermal therapy can be performed after the surgicalprocedure to implant the thermal device. Later, the fluid inlet andoutlet conduits 920, 922 can be decoupled from the bone anchor 904 in anon-surgical or minimally-invasive procedure by simply pulling theconduits through the closed incision.

In the thermal device 902, the positioning of the fluid conduits 920,922 beneath the U-shaped recess 910 can advantageously leave theU-shaped recess clear to receive a spinal fixation element. Accordingly,localized thermal therapy can be delivered via the thermal device 902before, during, and/or after a spinal fixation element is secured to thebone anchor 904 without interfering with the installation of the spinalfixation element.

The illustrated device 902 uses a single tube 924 extending distallyfrom the plug 906 and a cannulation 918 of the bone anchor 904 to definea fluid path through the distal portion of the bone anchor. It will beappreciated, however, that other variations are also possible, includingany of those described above with respect to FIGS. 2A-3C.

FIGS. 10A-10B illustrate an exemplary thermal device 1002. Except asindicated below, the structure and operation of the thermal device 1002is substantially identical to the thermal device 902, and therefore adetailed description is omitted here for the sake of brevity. In thethermal device 1002, the inlet and outlet conduits 1020, 1022 can exitthe bone anchor 1004 on the same side of the bone anchor. Accordingly,the bone anchor 1004 can include only a single cut-out or relief 1014formed beneath or distal to the U-shaped recess 1010 on only a singleside of the tulip 1008.

FIGS. 11A-11B illustrate an exemplary thermal device 1102. Except asindicated below, the structure and operation of the thermal device 1102is substantially identical to the thermal device 902, and therefore adetailed description is omitted here for the sake of brevity. In thethermal device 1102, the plug 1106 sits proud of the bore 1107 formed inthe bone anchor 1104 and the plug can include first and second lateralextensions 1109 that are received in the U-shaped recess 1110 definedbetween the opposed arms of the tulip. Accordingly, it is not necessarythat the tulip 1108 include cut-outs or reliefs formed beneath or distalto the U-shaped recess 1110, and therefore the plug 1106 can be usedwith any of a variety of standard, off-the-shelf bone anchors. The fluidinlet and outlet conduits 1120, 1122 can be oriented to extend laterallyoutward, substantially perpendicular to a longitudinal axis of the tulip1108.

FIGS. 12A-12C illustrate an exemplary thermal device 1202. Except asindicated below, the structure and operation of the thermal device 1202is substantially identical to the thermal device 902, and therefore adetailed description is omitted here for the sake of brevity. In thethermal device 1202, the plug 1206 sits proud of the bore formed in thebone anchor 1204 and the plug can include first and second lateralextensions 1209 that are received in the U-shaped recess 1210 definedbetween the opposed arms of the tulip 1208. Accordingly, it is notnecessary that the tulip 1208 include cut-outs or reliefs formed beneathor distal to the U-shaped recess 1210, and therefore the plug 1206 canbe used with any of a variety of standard, off-the-shelf bone anchors.The fluid inlet and outlet conduits 1220, 1222 can be oriented to extendsubstantially parallel to a longitudinal axis of the tulip 1208. Theplug 1206 can include a distal extension 1211 sized and shaped to fitwithin or form a substantial negative of a driving interface of the boneanchor 1204, such that the distal extension can be received within thedriving interface to couple the plug to the bone anchor. The plug 1206can also include gripping features 1213 (e.g., a plurality of parallelribs or protrusions) formed on the lateral extensions 1209 of the plugto facilitate coupling or decoupling of the plug to the bone anchor.

FIGS. 12D-12F illustrate an exemplary thermal device 1202′. Except asindicated below, the structure and operation of the thermal device 1202′is substantially identical to the thermal device 902, and therefore adetailed description is omitted here for the sake of brevity. In thethermal device 1202′, the plug 1206 sits proud of the bore formed in thebone anchor (not shown) and the plug can include first and secondlateral extensions 1209 that are received in the U-shaped recess definedbetween the opposed arms of the tulip. Accordingly, it is not necessarythat the tulip include cut-outs or reliefs formed distal to the U-shapedrecess, and therefore the plug 1206 can be used with any of a variety ofstandard, off-the-shelf bone anchors. The fluid inlet and outletconduits 1220, 1222 can be oriented to extend substantially parallel toa longitudinal axis of the tulip. The plug 1206 can include a distalextension 1211 sized and shaped to fit within or form a substantialnegative of a driving interface of the bone anchor, such that the distalextension can be received within the driving interface to couple theplug to the bone anchor. A sealing member such as an O-ring 1215 can beseated within a groove 1217 formed in the distal extension 1211 to forma seal between the plug 1206 and the bone anchor 1204 when the plug isseated therein. The plug 1206 can also include an elongate tube 1224that extends through the distal extension 1211 and extends distallytherefrom, such that the tube is configured to be received within acannulation of a bone anchor. The cannulation can be closed at thedistal end, such that the tube forms a fluid delivery path and thecannulation of the screw forms a fluid return path. As shown in FIG.12E, the plug 1206 can be formed from multiple components to facilitatemanufacturing. In particular, the plug 1206 can include a main housing1230 in which a recess 1232 is machined and an insert 1234 that definesfirst and second fluid pathways 1236, 1238 therein. The insert 1234 canbe received within the recess of the main housing 1230 to assemble theplug. When assembled, a first fluid pathway 1236 of the insert can be influid communication with the tube 1224, and a second fluid pathway 1238of the insert can be in fluid communication with the recess 1232 formedin the main housing and the cannulation of a bone anchor in which theplug is inserted.

FIGS. 13A-13D illustrate an exemplary thermal device 1302. The device1302 generally includes an elongate sleeve 1304 (e.g., a screw extensionor tower) configured to couple to a bone anchor 1306. In someembodiments, the thermal device 1302 can provide a minimally-invasivepathway between a skin incision at a proximal end of the device and abone anchor disposed at a distal end of the device through whichimplants such as spinal fixation elements can be inserted. The sleeve1304 can include an elongate tubular body with opposed cut-outs formedin a distal end thereof to define first and second opposed distal tabs1308. The tabs 1308 can include one or more mating features for couplingthe thermal device to the bone anchor. For example, the inner surfacesof the tabs can include a recess 1310 configured to receive a protrusion1312 formed on the tulip portion 1314 of the bone anchor. Alternatively,or in addition, the inner surfaces of the tabs 1308 can include aprojection configured to be received within a recess formed in the tulipportion.

The sleeve 1304 can include one or more fluid passages defined thereinthrough which heated or cooled fluid can be circulated to apply athermal effect to a bone anchor to which the device is coupled andtissue proximate thereto. In the illustrated embodiment, the sleeve 1304includes two dual-lumen fluid loops 1316 formed in diametrically-opposedpositions about the circumference of the sleeve. Each loop 1316 caninclude an inlet portion that extends from a proximal end of the sleeveto a distal fluid chamber 1318 and an outlet portion that extends fromthe distal fluid chamber to the proximal end of the sleeve. The fluidloops 1316 can be aligned with the tabs 1308 of the sleeve such that thefluid loops extend into a portion of the sleeve configured to beadjacent to the bone anchor 1306 when the bone anchor is coupled to thesleeve. The fluid loops 1316 can be embedded within the sleeve such thatthe sleeve has a constant, cylindrical outside diameter, as shown inFIG. 13C. The fluid loops 1316 can also be coupled to the exteriorsidewall of the sleeve, or embedded in protrusions formed in theexterior sidewall of the device, as shown in FIG. 13D. Fluid conduits1320 can be coupled to the proximal end of the sleeve 1304 to deliverand extract fluid from the device. In the illustrated embodiment, eachconduit includes multiple internal lumens (e.g., an inlet lumen and anoutlet lumen).

Cross-Connector Thermal Devices

FIG. 14A-14B illustrate an exemplary thermal device 1402. The device1402 generally includes a connector configured to couple a first spinalfixation element (e.g., a first spinal rod) to a second spinal fixationelement (e.g., a second spinal rod). For example, the connector can beused as a cross-connector to couple first and second spinal rods R1, R2disposed on contralateral sides of a patient's spinal column SC to oneanother. The connector can include first and second recesses 1404, 1406configured to receive corresponding first and second spinal fixationelements therein. The connector can also include one or more lockingelements (e.g., cams, set screws, bolts, etc.) configured to secureand/or lock the connector to the spinal fixation elements. The connectorcan have multiple points of contact with the first and second spinalrods. While a unitary connector is shown, it will be appreciated thatthe connector can include multiple components coupled to one another ina movable relationship and/or such that the position and orientation ofthe components can be locked relative to one another. For example, therod receiving recesses can 1404, 1406 can be formed in components whichare separate from a main body of the connector. The rod-receivingcomponents can be movable relative to the main body (e.g., rotatable,translatable, etc.).

The connector 1402 can include a cavity 1408 formed therein throughwhich heated or chilled fluid can be circulated to apply a thermaleffect to the connector and to tissue proximate thereto. For example, asshown in FIG. 14B, the cavity 1408 can be disposed adjacent a patient'sspinal canal SC when the connector 1402 is coupled to first and secondspinal rods R1, R2 disposed on contralateral sides of the patient'sspinal column. In embodiments in which the connector includes multiplecomponents, the cavity can be formed in any one or more of the separatecomponents. The device 1402 can include inlet and outlet conduitsconfigured to supply and withdraw fluid, respectively, from the cavity.The conduits can be selectively detachable from the connector 1402 tofacilitate post-surgical withdrawal of the conduits. A multi-lumenconduit 1410 that includes an inlet lumen and an outlet lumen can becoupled to the connector 1402 at a substantial midpoint of the connectoras shown. Alternatively, or in addition, discrete inlet and outletconduits can be coupled to the connector 1402 at opposed ends of thechamber 1408 to facilitate directional flow of fluid through thechamber. In some embodiments, the connector 1402 can have a width of atleast about 5 mm. In some embodiments, the connector can have a width ofat least about 10 mm.

In use, the device 1402 can be coupled to first and second spinalfixation elements R1, R2 to augment a fixation or stabilizationconstruct or to provide physical protection to an exposed spinal canalSC. Cooled or heated fluid can be circulated through the cavity 1408 ofthe device 1402 to apply localized thermal therapy to a target treatmentregion disposed beneath or proximate to the cavity (e.g., the dura of apatient's spinal canal). After completion of the thermal therapy, or atany other desired time, the inlet and outlet conduits can be separatedfrom the device (e.g., by pulling the conduits proximally) and theconnector 1402 can be left in place indefinitely. As described infurther detail below, the patient can be closed up with just the inletand outlet conduits extending through the closed incision, such thatthermal therapy can be performed after the surgical procedure to implantthe thermal device 1402. Later, the fluid inlet and outlet conduits canbe decoupled from the connector 1402 in a non-surgical orminimally-invasive procedure by simply pulling the conduits through theclosed incision.

FIG. 15 illustrates an exemplary thermal device 1502. Except asindicated below, the structure and operation of the thermal device 1502is substantially identical to the thermal device 1402, and therefore adetailed description is omitted here for the sake of brevity. Thethermal device 1502 includes discrete inlet and outlet conduits 1510,1512 coupled to the connector 1502 at opposed ends of the chamber 1508to facilitate directional flow of fluid through the chamber. The thermaldevice 1502 can also include a balloon or inflatable member 1514 thatcan be inflated with thermal media circulated through the chamber tobring the inflatable member closer to or into contact with a targettreatment site (e.g., the dura of the spinal canal). The connector 1502can be rigid or semi-rigid and can include a window 1516 through whichthe inflatable member 1514 can selectively protrude. The inflatablemember 1514 can have an inflated configuration in which it protrudesthrough the window and into close proximity or into contact with thetarget treatment site. The inflatable member 1514 can also have adeflated configuration in which it does not protrude through the windowor protrudes through the window to a lesser degree than when in theinflated configuration. In use, the device 1502 can be coupled to firstand second spinal fixation elements R1, R2 to augment a fixation orstabilization construct or to provide physical protection to an exposedspinal canal. Cooled or heated fluid can be circulated through thecavity 1508 of the device to expand the inflatable member 1514 intoproximity to or contact with the patient's dura to apply localizedthermal therapy thereto. After completion of the thermal therapy, or atany other desired time, the inlet and outlet conduits 1510, 1512 can beseparated from the device (e.g., by pulling the conduits proximally) andthe connector 1502 can be left in place indefinitely. The inflatablemember 1514 can be fixedly attached to at least one of the conduits1510, 1512 such that pulling out said conduit is effective to also pullthe inflatable member out of the device 1502. As described in furtherdetail below, the patient can be closed up with just the inlet andoutlet conduits extending through the closed incision, such that thermaltherapy can be performed after the surgical procedure to implant thethermal device. Later, the fluid inlet and outlet conduits can bedecoupled from the connector in a non-surgical or minimally-invasiveprocedure by simply pulling the conduits through the closed incision.

Spinous Process Thermal Devices

FIGS. 16A-16D illustrate an exemplary thermal device 1602. The device1602 can be configured for use as a spinous process spacer or a spinousprocess fixation device. The device 1602 generally includes first andsecond opposed plates 1604 separated by a hub or bridge portion 1606that joins the two plates to form an H-shaped construct. Each plate 1604can include a superior wing portion 1608 configured for placementagainst a lateral surface of a spinous process 1610 of a superiorvertebra and an inferior wing portion 1612 configured for placementagainst a lateral surface of a spinous process 1614 of an inferiorvertebra. It will be appreciated that the superior and inferiorvertebrae need not necessarily be adjacent, and that each plate 1604 canhave a length suitable for placing the plate against the spinousprocesses of non-adjacent vertebrae. The bone facing surfaces of eachplate 1604 can include one or more teeth or other gripping features toengage a spinous process against which the plate is placed.Alternatively, or in addition, the bone-facing surfaces of the plates1604 can include one or more openings or holes through which screws orother anchors can be inserted to fixedly attach the plate to adjacentbone.

The bridge portion 1606 can include a cavity 1616 formed therein throughwhich heated or chilled fluid can be circulated to apply a thermaleffect to the device 1602 and to tissue proximate thereto. For example,as shown in FIG. 16D, the cavity 1616 can be disposed adjacent apatient's spinal canal SC when the device is coupled to superior andinferior spinous processes 1610, 1614. The device 1602 can include inletand outlet conduits configured to supply and withdraw fluid,respectively, from the cavity 1616. The conduits can be selectivelydetachable from the device to facilitate post-surgical withdrawal of theconduits. A multi-lumen conduit 1618 that includes an inlet lumen and anoutlet lumen can be coupled to the device at a substantial midpoint ofthe chamber 1616 as shown. Alternatively, or in addition, discrete inletand outlet conduits can be coupled to the device 1602 at opposed ends ofthe chamber 1616 to facilitate directional flow of fluid through thechamber.

In use, the device 1602 can be coupled to superior and inferior spinousprocesses 1610, 1614 such that the spinous processes are receivedbetween the opposed plates 1604 of the device and the bridge portion1606 of the device is disposed between the spinous processes, as shownin FIG. 16C. Cooled or heated fluid can be circulated through the cavity1616 of the device to apply localized thermal therapy to a targettreatment region disposed beneath the cavity (e.g., the dura of apatient's spinal canal). After completion of the thermal therapy, or atany other desired time, the inlet and outlet conduits can be separatedfrom the device (e.g., by pulling the conduits proximally) and thedevice can be left in place indefinitely. As described in further detailbelow, the patient can be closed up with just the inlet and outletconduits extending through the closed incision, such that thermaltherapy can be performed after the surgical procedure to implant thethermal device. Later, the fluid inlet and outlet conduits can bedecoupled from the device in a non-surgical or minimally-invasiveprocedure by simply pulling the conduits through the closed incision.

FIGS. 17A-17D illustrate an exemplary thermal device 1702. Except asindicated below, the structure and operation of the thermal device 1702is substantially identical to the thermal device 1602, and therefore adetailed description is omitted here for the sake of brevity. In thethermal device 1702, one of the plates can be omitted such that thedevice includes only a single plate 1704 and the bridge portion 1706.The device 1702 can be coupled to superior and inferior spinousprocesses 1710, 1714 on only a single side of said spinous processes, asshown in FIG. 17C.

FIGS. 18A-18C illustrate an exemplary thermal device 1802. Except asindicated below, the structure and operation of the thermal device 1802is substantially identical to the thermal device 1702, and therefore adetailed description is omitted here for the sake of brevity. In thethermal device 1802, the cavity 1816 is not necessarily confined to thebridge portion 1806, but rather can extend into some or all of the plate1804. While a single plate arrangement is shown, it will be appreciatedthat the device 1802 can include first and second plates (e.g., as shownand described above with respect to FIGS. 16A-16D) and the cavity 1816can extend into each of the first and second plates.

FIGS. 19A-19C illustrate an exemplary thermal device 1902. Except asindicated below, the structure and operation of the thermal device 1902is substantially identical to the thermal device 1802, and therefore adetailed description is omitted here for the sake of brevity. In thethermal device 1902, the bridge portion can be omitted such that thedevice includes only a single plate portion 1904 in which a cavity 1916is defined for circulating cooled or heated fluid. The inlet and outletconduit(s) 1918 can be coupled directly to the plate portion 1904 asshown.

FIGS. 20A-20C illustrate an exemplary thermal device 2002. The thermaldevice 2002 generally includes an elongate shield or plate 2004configured to be positioned over a midline of a patient's spinal canalafter one or more spinous processes of the patient's spinal column havebeen removed. The plate 2004 can be configured to protect the spinalcanal contents and to apply localized thermal therapy thereto. The plate2004 can be positioned such that a central longitudinal axis of theplate is disposed over and substantially in parallel to a midline of apatient's spinal column.

The plate 2004 can include connection features at each end thereof forattaching the plate to the patient's spinal column. In the illustratedembodiment, each end of the plate 2004 includes a flange 2006 thatdefines first and second lateral wings 2008. An opening 2010 configuredto receive a bone screw or other anchoring device can be formed in eachof the wings to facilitate attachment of the plate 2004 to bonystructures of the spinal column (e.g., pedicles, lateral mass, etc.).

As shown in FIG. 20C, the plate 2004 can curve in one or more planesalong a length thereof. For example, as shown, the plate can be bowedsuch that a central portion of the plate is disposed in close proximityor in contact with the dura of the patient's spinal canal when the plateis attached to the spinal column.

The plate 2004 can include a cavity 2012 formed therein through whichheated or chilled fluid can be circulated to apply a thermal effect tothe device 2002 and to tissue proximate thereto. For example, the cavity2012 can be disposed adjacent a patient's spinal canal when the deviceis coupled to superior and inferior vertebrae of the patient. The device2002 can include inlet and outlet conduits configured to supply andwithdraw fluid, respectively, from the cavity. The conduits can beselectively detachable from the device to facilitate post-surgicalwithdrawal of the conduits. A multi-lumen conduit 2014 that includes aninlet lumen and an outlet lumen can be coupled to the device at asubstantial midpoint of the chamber 2012 as shown. Alternatively, or inaddition, discrete inlet and outlet conduits can be coupled to thedevice at opposed ends of the chamber 2012 to facilitate directionalflow of fluid through the chamber.

The plate 2004 can also be made wider to cover a broader area of thepatient's spinal canal. A wider version of the plate 2004 is shown inFIGS. 20D-20E. In some embodiments, the portion P of the plate disposedover the spinal canal can have a minimum width W of at least about 15mm.

In use, the device 2002 can be coupled to superior and inferiorvertebrae (e.g., after removal of the spinous processes from thesuperior and inferior vertebrae and any intervening vertebrae). Cooledor heated fluid can be circulated through the cavity 2012 of the deviceto apply localized thermal therapy to a target treatment region disposedbeneath the cavity (e.g., the dura of a patient's spinal canal). Aftercompletion of the thermal therapy, or at any other desired time, theinlet and outlet conduits 2014 can be separated from the device (e.g.,by pulling the conduits proximally) and the device 2002 can be left inplace indefinitely. As described in further detail below, the patientcan be closed up with just the inlet and outlet conduits extendingthrough the closed incision, such that thermal therapy can be performedafter the surgical procedure to implant the thermal device. Later, thefluid inlet and outlet conduits can be decoupled from the device in anon-surgical or minimally-invasive procedure by simply pulling theconduits through the closed incision.

FIGS. 21A-21C illustrate an exemplary thermal device 2102. The device2102 can be configured for use as a spinous process spacer or a spinousprocess fixation device. The device 2102 generally includes a firstplate 2104 having a hub or bridge portion 2106 extending therefrom and asecond plate 2108 having an opening 2110 in which the bridge portion isslidably received to form an H-shaped construct. The device 2102 canalso include one or more locking elements configured to lock a relativeposition of the second plate 2108 along the bridge portion 2106 or, inother words, to lock a fixed distance between the first and secondplates 2104, 2108.

Each plate 2104, 2108 can include a superior wing portion configured forplacement against a lateral surface of a spinous process of a superiorvertebra and an inferior wing portion configured for placement against alateral surface of a spinous process of an inferior vertebra. It will beappreciated that the superior and inferior vertebrae need notnecessarily be adjacent, and that each plate can have a length suitablefor placing the plate against the spinous processes of non-adjacentvertebrae. The bone facing surfaces of each plate can include one ormore teeth or other gripping features 2112 to engage a spinous processagainst which the plate is placed. Alternatively, or in addition, thebone-facing surfaces of the plates can include one or more openings orholes 2114 through which screws or other anchors can be inserted tofixedly attach the plate to adjacent bone.

The bridge portion 2106 can extend perpendicular to the first plate 2104and can be slidably received within the opening 2110 in the second plate2108. While the bridge can have any of a variety of cross-sectionalshapes, in the illustrated embodiment the bridge includes a concaveanterior-facing surface 2106A configured to be disposed over a patient'sspinal canal and a convex posterior-facing surface 2106P configured tobe engaged by the one or more locking elements.

In the illustrated embodiment, the second plate 2108 includes first andsecond threaded openings in which first and second set screws 2116 arethreadably received. The first and second set screws can be advancedwithin the openings to engage distal ends of the set screws with theposterior-facing surface 2106P of the bridge 2106, thereby locking arelative position of the second plate 2108 relative to the bridge. Theset screws 2116 can be at least partially opposed to one another suchthat they are advanced towards each other as they are tightened. Forexample, a longitudinal axis of a first set screw can extend at anoblique angle α with respect to a longitudinal axis of the second setscrew. It will be appreciated that, while set screws are shown in theillustrated embodiment, any of a variety of locking elements can be usedalternatively or in addition. The use of plural locking elements canadvantageously provide redundancy in the event that one of the lockingelements becomes loosened or disengaged over time.

Any of the first plate 2104, the second plate 2108, and the bridgeportion 2106 can include a cavity formed therein through which heated orchilled fluid can be circulated to apply a thermal effect to the device2102 and to tissue proximate thereto. For example, the cavity can beformed in the bridge portion 2106 and can be disposed adjacent apatient's spinal canal when the device is coupled to superior andinferior spinous processes. The device 2102 can include inlet and outletconduits configured to supply and withdraw fluid, respectively, from thecavity. The conduits can be selectively detachable from the device tofacilitate post-surgical withdrawal of the conduits. A multi-lumenconduit that includes an inlet lumen and an outlet lumen can be coupledto the device at a substantial midpoint of the chamber. Alternatively,or in addition, discrete inlet and outlet conduits can be coupled to thedevice at opposed ends of the chamber to facilitate directional flow offluid through the chamber.

The device 2102 can include one or more sensors 2118 (e.g., temperatureprobes or sensors) embedded in the plates or the bridge portion, orinserted through said portions. As shown in FIG. 21C, the device 2012can include a flexible sensor 2120 (e.g., a contact flex thermocouple)configured to flex into contact with or into close proximity to a targetarea disposed beneath the bridge portion 2106 when the device isimplanted in a patient. In some embodiments, sliding the second plate2108 along the bridge portion 2106 towards the first plate 2104 can beeffective to bend the flexible sensor 2120 such that the sensor movestowards a target region disposed beneath the bridge.

In use, the device 2102 can be coupled to superior and inferior spinousprocesses such that the spinous processes are received between theopposed plates 2104, 2108 of the device and the bridge portion 2106 ofthe device is disposed between the spinous processes. The plates can bemoved towards each other to firmly engage the lateral sides of thespinous processes, and the one or more locking elements 2116 can beactuated to fix the distance between the plates. Once implanted, thedevice 2102 can be used to monitor one or more physiological parameters(e.g., temperature, pressure, pH, etc.) as localized thermal therapy isperformed. Cooled or heated fluid can be circulated through a cavity ofthe device 2102 to apply localized thermal therapy to a target treatmentregion disposed beneath the cavity (e.g., the dura of a patient's spinalcanal). After completion of the thermal therapy, or at any other desiredtime, the inlet and outlet conduits can be separated from the device(e.g., by pulling the conduits proximally) and the device can be left inplace indefinitely. As described in further detail below, the patientcan be closed up with just the inlet and outlet conduits extendingthrough the closed incision, such that thermal therapy can be performedafter the surgical procedure to implant the thermal device. Later, thefluid inlet and outlet conduits can be decoupled from the device in anon-surgical or minimally-invasive procedure by simply pulling theconduits through the closed incision.

Rod Thermal Devices

FIGS. 22A-22C illustrate an exemplary thermal device 2202. The device2202 can be configured for use as a spinal fixation or stabilizationrod. The device 2202 generally includes an elongate rod 2204 having acannulation 2206 formed along at least a portion of the length of therod. The cannulation can define a cavity through which heated or chilledfluid can be circulated to apply a thermal effect to the device and totissue proximate thereto. The device 2202 can include inlet and outletconduits configured to supply and withdraw fluid, respectively, from thecannulation. The conduits can be selectively detachable from the deviceto facilitate post-surgical withdrawal of the conduits. A multi-lumenconduit that includes an inlet lumen and an outlet lumen can be coupledto the device at one end of the cannulation and the opposite end of thecannulation can be closed. Alternatively, discrete inlet and outletconduits can be coupled to the device at opposed ends of the cannulationto facilitate directional flow of fluid through the device. As shown inFIG. 22B, the inlet and/or outlet conduits 2210 can be coupled to therod using a barbed fitting 2208 formed on or coupled to an end of therod 2204 to form a fluid tight connection and place the cannulation 2206of the thermal device in fluid communication with the inlet and/oroutlet conduit. While the barbed fitting 2208 is shown as part of therod 2204, it will be appreciated that the fitting can be formed on theconduit 2210 instead and can be received within the cannulation 2206 ofthe rod. As shown in FIG. 22C, the inlet and/or outlet conduits 2210 canbe coupled to the rod 2204 using a tapered fitting 2212 to form a fluidtight connection and place the cannulation 2206 of the thermal device influid communication with the inlet and/or outlet conduit. The fitting2212 can include an inner tapered portion formed from a first material(e.g., steel) and an outer tubular portion formed from a second materialthat is different from the first material (e.g., plastics, elastomers,etc.). While the tapered fitting is shown as being inserted into thecannulation 2206 of the rod 2204, it will be appreciated that this canbe reversed such that the fitting is formed on or coupled to the rod andinserted into the interior of the conduit 2210. A threaded connectioncan also be used to couple the conduit(s) to the thermal device 2202.The fittings of FIGS. 22B and 22C can also be used to couple withvarious other devices other than spinal rods.

In use, the device 2202 can be anchored to the spine using one or morebone anchors (e.g., first and second bone screws). For example, thedevice 2202 can be seated in the U-shaped recesses of a plurality ofbone screws and secured thereto using set screws. By way of furtherexample, the device 2202 can be seated in side-entry outriggers of aplurality of bone anchors 2300, as shown in FIGS. 23A and 23B. Theoutriggers 2301 can include opposed arms that define a rod-receivingrecess, the opposed arms extending substantially perpendicular to thearms that define the primary U-shaped recess in the bone anchor. Theoutriggers 2301 can be configured to receive the thermal device 2202 ina snap-fit or press-fit engagement. The thermal device 2202 can also becoupled to the outriggers by a locking mechanism such as a set screw orlocking nut. In some embodiments, a first thermal device can be seatedin the U-shaped recesses of the bone anchors and a second thermal devicecan be seated in the outriggers. In other embodiments, a traditionalspinal rod can be seated in the U-shaped recesses of the bone anchorsand the thermal device can be seated in the outriggers. Cooled or heatedfluid can be circulated through the cannulation of the device to applylocalized thermal therapy to a target treatment region disposed inproximity to the device or to bone anchors to which the device iscoupled. After completion of the thermal therapy, or at any otherdesired time, the inlet and outlet conduits can be separated from thedevice (e.g., by pulling the conduits proximally) and the device can beleft in place indefinitely. As described in further detail below, thepatient can be closed up with just the inlet and outlet conduitsextending through the closed incision, such that thermal therapy can beperformed after the surgical procedure to implant the thermal device.Later, the fluid inlet and outlet conduits can be decoupled from thedevice in a non-surgical or minimally-invasive procedure by simplypulling the conduits through the closed incision.

Instrument Thermal Devices

FIG. 24 illustrates an exemplary thermal device 2402. The device 2402can be configured for use as a pedicle marker or probe. The device 2402generally includes an elongate shaft 2404 having a tapered distal end2406. The shaft 2404 can include a cannulation 2408 formed along atleast a portion of the length of the shaft. The cannulation 2408 candefine a cavity through which heated or chilled fluid can be circulatedto apply a thermal effect to the device 2402 and to tissue proximatethereto. The device 2402 can include inlet and outlet conduitsconfigured to supply and withdraw fluid, respectively, from thecannulation. The conduits can be selectively detachable from the deviceto facilitate post-surgical withdrawal of the conduits. A multi-lumenconduit that includes an inlet lumen and an outlet lumen can be coupledto the device at a proximal end of the cannulation and the distal end ofthe cannulation can be closed.

In use, the device 2402 can be used as a pedicle marker or probe. A holecan be drilled into a bony structure of the patient and the tapereddistal tip 2406 of the thermal device 2402 can be inserted into thehole. Cooled or heated fluid can be circulated through the cannulation2408 of the device to apply localized thermal therapy to the bone inwhich the hole is formed and tissue proximate thereto. After completionof the thermal therapy, or at any other desired time, the inlet andoutlet conduits can be separated from the device (e.g., by pulling theconduits proximally).

FIG. 25 illustrates an exemplary thermal device 2502. The device 2502can be configured for use as bone tap or drill bit. The device 2502generally includes an elongate shaft 2504 having a threaded or bladeddistal end 2506. The distal end can include one or more flutes 2510 tofacilitate self-tapping of a bone hole using the device. The shaft 2504can include a cannulation 2508 formed along at least a portion of thelength of the shaft. The cannulation 2508 can define a cavity throughwhich heated or chilled fluid can be circulated to apply a thermaleffect to the device 2502 and to tissue proximate thereto. The device2502 can include inlet and outlet conduits configured to supply andwithdraw fluid, respectively, from the cannulation. The conduits can beselectively detachable from the device to facilitate post-surgicalwithdrawal of the conduits. A multi-lumen conduit that includes an inletlumen and an outlet lumen can be coupled to the device at a proximal endof the cannulation and the distal end of the cannulation can be closed.

In use, the device 2502 can be used as a bone tap or drill bit forforming a hole in a bony structure of the patient. Before, during, orafter advancing the device 2502 into bone, cooled or heated fluid can becirculated through the cannulation 2508 of the device to apply localizedthermal therapy to the bone and tissue proximate thereto. Aftercompletion of the thermal therapy, or at any other desired time, theinlet and outlet conduits can be separated from the device 2502 (e.g.,by pulling the conduits proximally).

Bone Plug and Bone Plate Thermal Devices

FIGS. 26A-26B illustrate an exemplary thermal device 2602. The thermaldevice 2602 generally includes a bone plug 2604 configured to beinserted into a hole formed in a bone structure of a patient to applylocalized thermal therapy thereto. The plug 2604 can include acylindrical distal projection 2606 sized and configured to be receivedin a bone hole. In some embodiments, the cylindrical distal projection2606 can be non-threaded. The plug 2604 can also include a proximal bodyportion 2608 to facilitate grasping and manipulation of the plug.

The plug 2604 can include a cavity 2610 formed therein through whichheated or chilled fluid can be circulated to apply a thermal effect tothe device 2602 and to tissue proximate thereto. The device 2602 caninclude inlet and outlet conduits 2612, 2614 configured to supply andwithdraw fluid, respectively, from the cavity 2610. The conduits can beselectively detachable from the device to facilitate post-surgicalwithdrawal of the conduits. A multi-lumen conduit that includes an inletlumen and an outlet lumen can be coupled to a proximal end of the deviceas shown. Alternatively, or in addition, discrete inlet and outletconduits can be coupled to the device.

In use, a bone structure of a patient can be prepared by forming a drillhole (e.g., a blind bore) in the bone. Exemplary bone structures includea vertebra, a vertebral body, a lamina, a spinous process, a lateralmass, a pedicle, and any other bone in a human or animal body. Thedistal projection 2606 of the device 2602 can then be inserted into thebone hole. The bone hole can be sized such that a slight interferencefit is formed between the plug 2604 and bone hole to help maintain theplug in position within the bone hole. Cooled or heated fluid can becirculated through the cavity 2610 of the device 2602 to apply localizedthermal therapy to the bone in which the bone hole is formed and totissue proximate thereto. After completion of the thermal therapy, or atany other desired time, the inlet and outlet conduits can be separatedfrom the device (e.g., by pulling the conduits proximally) and thedevice can be left in place indefinitely. Alternatively, the device canbe removed with the inlet and outlet conduits. As described in furtherdetail below, the patient can be closed up with just the inlet andoutlet conduits extending through the closed incision, such that thermaltherapy can be performed after the surgical procedure to implant thethermal device. Later, the fluid inlet and outlet conduits can bedecoupled from the device in a non-surgical or minimally-invasiveprocedure by simply pulling the conduits through the closed incision.Alternatively, the fluid inlet and outlet conduits and the bone plugitself can be removed together in a non-surgical or minimally-invasiveprocedure by simply pulling the conduits and the bone plug through theclosed incision.

FIGS. 27A-27B illustrate an exemplary thermal device 2702. Except asindicated below, the structure and operation of the thermal device 2702is substantially identical to the thermal device 2602, and therefore adetailed description is omitted here for the sake of brevity. In thethermal device 2702, the proximal body portion 2708 can be in the formof an enlarged plate configured to lie against the bone structure inwhich the bone hole is formed when the distal projection 2706 of thethermal device 2702 is seated in the bone hole. As shown in FIG. 27B,the cavity 2710 can extend into the distal projection of the plug aswell as laterally throughout the plate portion 2708 of the plug. Thethermal device 2702 can advantageously provide a broader application oflocalized thermal therapy given the increased contact surface areaprovided by the plate portion 2708.

FIGS. 28A-28B illustrate an exemplary thermal device 2802. Except asindicated below, the structure and operation of the thermal device 2802is substantially identical to the thermal device 2702, and therefore adetailed description is omitted here for the sake of brevity. In thethermal device 2802, the proximal plate portion 2808 includes one ormore openings 2816 formed therein configured to receive a bone anchor2818 (e.g., a bone screw) to secure the plate to bone. As shown in FIG.28B, the openings 2816 can define tunnels that extend through the fluidcavity 2810, such that the cavity extends around the openings. Thethermal device 2802 can advantageously provide a more secure attachmentto bone.

FIGS. 29A-29B illustrate an exemplary thermal device 2902. Except asindicated below, the structure and operation of the thermal device 2902is substantially identical to the thermal device 2802, and therefore adetailed description is omitted here for the sake of brevity. In thethermal device 2902, the distal projection of the device is omitted suchthat the body of the device includes only the proximal plate portion2908. The thermal device 2902 can advantageously be used without theneed to first form a bone hole to receive a plug portion of the device.

FIGS. 30A-30B illustrate an exemplary thermal device 3002. The thermaldevice 3002 generally includes a bone plate 3004 and one or more boneanchor thermal devices 3006 (e.g., of the type described above). Thebone plate 3004 can include one or more openings through which the boneanchor thermal devices 3006 can be inserted to couple the bone plate toa bone structure of a patient. Each of the bone anchor thermal devices3006 can include a cavity 3008 formed therein through which heated orchilled fluid can be circulated to apply a thermal effect to the boneanchor, the plate, and to tissue proximate thereto. The bone anchorthermal devices 3006 can include inlet and outlet conduits configured tosupply and withdraw fluid, respectively, from the cavity. The conduitscan be selectively detachable from the bone anchors to facilitatepost-surgical withdrawal of the conduits. A multi-lumen conduit 3010that includes an inlet lumen and an outlet lumen can be coupled to aproximal end of the bone anchor 3006 as shown. Alternatively, or inaddition, discrete inlet and outlet conduits can be coupled to the boneanchor 3006.

In use, the plate 3004 can be secured to a bone structure of a patientby inserting the bone anchor thermal devices 3006 through the openingsin the plate and anchoring the bone anchors in the bone. Exemplary bonestructures include a vertebra, a vertebral body, a lamina, a spinousprocess, a lateral mass, a pedicle, and any other bone in a human oranimal body. Cooled or heated fluid can be circulated through thecavities 3008 of the one or more bone anchor thermal devices 3006 toapply localized thermal therapy to the plate 3004 and the bone to whichthe plate is coupled. After completion of the thermal therapy, or at anyother desired time, the inlet and outlet conduits 3010 can be separatedfrom the bone anchors 3006 (e.g., by pulling the conduits proximally)and the bone anchors and the plate 3004 can be left in placeindefinitely. As described in further detail below, the patient can beclosed up with just the inlet and outlet conduits extending through theclosed incision, such that thermal therapy can be performed after thesurgical procedure to implant the thermal device. Later, the fluid inletand outlet conduits can be decoupled from the device in a non-surgicalor minimally-invasive procedure by simply pulling the conduits throughthe closed incision.

Clamp Thermal Devices

FIGS. 31A-31C illustrate an exemplary thermal device 3102. The thermaldevice 3102 generally includes a clamp configured to grasp an implant oran anatomical structure to apply localized thermal therapy thereto. Thedevice 3102 can include first and second opposed clamping arms 3104pivotally coupled to one another at a hinge 3106. The hinge 3106 can beor can include a pivot pin, a living hinge, or any of a variety of othermechanisms for pivotally coupling the first and second clamping arms3104 to one another.

One or both of the first and second clamping arms 3104 can include acavity 3108 formed therein through which heated or chilled fluid can becirculated to apply a thermal effect to the device 3102 and to animplant or anatomical structure grasped thereby. The device 3102 caninclude inlet and outlet conduits 3110 configured to supply and withdrawfluid, respectively, from each cavity 3108. The conduits 3110 can beselectively detachable from the device to facilitate post-surgicalwithdrawal of the conduits. A multi-lumen conduit 3110 that includes aninlet lumen and an outlet lumen can be coupled to a proximal end of eachof the opposed arms 3104 as shown. Alternatively, or in addition,discrete inlet and outlet conduits can be coupled to each arm.

The cavity 3108 of each arm 3104 can extend through and fillsubstantially the entire internal volume of the arm as shown in FIG.31B. Alternatively, the cavity 3108 can formed entirely in a distalportion of the arm 3104, with only a relatively small fluid passage 3112extending through the proximal portion of the arm to provide fluidcommunication between the cavity and the fluid inlet and outlet conduits3110. This can advantageously focus the thermal effect at the distal endof the device 3102 where the clamped object is disposed.

The opposed arms 3104 can define a clamping recess 3114 that issubstantially a negative of a structure to which the device 3102 is tobe clamped. For example, the clamping recess 3114 can be substantially anegative of the head of a bone screw, a spinal rod, a spinous processspacer, an interbody spacer, etc. By way of further example, theclamping recess 3114 can be substantially a negative of an anatomicalstructure such as a spinous process, a facet, a lateral mass, a pedicle,a lamina, etc.

In use, the device 3102 can be clamped onto an implant or an anatomicalstructure of a patient. When the anatomical structure is a bone, thebone can be prepared for delivery of thermal therapy, for example byremoving any soft tissue overlying the bone and/or decorticating thebone. Exemplary bone structures include a vertebra, a vertebral body, alamina, a spinous process, a lateral mass, a pedicle, and any other bonein a human or animal body. Cooled or heated fluid can be circulatedthrough one or more cavities 3108 of the device 3102 to apply localizedthermal therapy to the object which is grasped by the device and totissue proximate thereto. Delivering a thermal effect through both ofthe clamping arms can advantageously provide more uniform application ofthe thermal effect to the object grasped by the device. After completionof the thermal therapy, or at any other desired time, the inlet andoutlet conduits 3110 can be separated from the device (e.g., by pullingthe conduits proximally) and the device 3102 can be left in placeindefinitely. Alternatively, the device can be removed with the inletand outlet conduits. As described in further detail below, the patientcan be closed up with just the inlet and outlet conduits extendingthrough the closed incision, such that thermal therapy can be performedafter the surgical procedure to implant the thermal device. Later, thefluid inlet and outlet conduits can be decoupled from the device in anon-surgical or minimally-invasive procedure by simply pulling theconduits through the closed incision.

Interbody Thermal Devices

FIGS. 32A-32C illustrate an exemplary thermal device 3202. The thermaldevice 3202 generally includes an implant 3204 (e.g., an interbodyspacer, a disc replacement member, or an interbody fusion device) and athermal probe 3206. The implant 3204 can include one or more thermallyconductive portions or surface features to facilitate transfer of aheating or cooling effect from the thermal probe 3206 to the implantwhen the thermal probe is placed in contact with the implant. In theillustrated embodiment, the implant 3204 generally includes an interbodyfusion spacer or cage 3208 sized and configured for insertion into adisc space via a lateral approach. The implant 3204 can include agenerally rectangular parallelepiped frame. Superior and inferiorsurfaces of the implant 3204 can include teeth, spikes, or serrations toenhance purchase with the vertebral endplates when the implant ispositioned in a disc space. At least one of the side surfaces of theimplant 3204 can include a thermally conductive plate or exteriorstructural member 3210 coupled thereto or embedded therein. For example,the posterior-facing surface 3204P of the implant, which can be inclosest proximity to the spinal canal when the implant is disposed in adisc space, can include or be covered with a thermally conductive plate.In the illustrated embodiment, both of the major sides 3204P, 3204A ofthe implant include a thermally conductive plate 3210 such that,regardless of the orientation in which the implant is inserted into thedisc space, the major surface facing the spinal canal will include athermally-conductive plate. The thermally-conductive plate 3210 caninclude one or more features for facilitating engagement with thethermal probe 3206. For example, the plate can include a recess 3212 inwhich at least a portion of the probe 3206 can be seated. The plate 3210can also include a threaded opening or various other mating features forselectively coupling the plate to the probe 3206.

The frame 3208 of the implant can be formed from any of a variety ofknown materials suitable for interbody devices, including polymers suchas PEEK. The thermally-conductive plate or plates 3210 can be formedfrom any of a variety of materials with high thermal conductivity, suchas titanium. The plates 3210 can be load bearing (e.g., configured tobear physiological loads typically exerted on spinal discs).

The thermal probe 3206 can include a cavity formed therein through whichheated or chilled fluid can be circulated to apply a thermal effect toan implant with which the probe is placed in contact. The probe 3206 caninclude inlet and outlet conduits configured to supply and withdrawfluid, respectively, from the cavity. For example, a multi-lumen conduitthat includes an inlet lumen and an outlet lumen can be coupled to aproximal end of the probe and the distal end of the probe can be closed.Alternatively, or in addition, discrete inlet and outlet conduits can becoupled to the device.

In use, the implant 3204 can be inserted into a disc space definedbetween vertebral bodies of a patient's spine, for example using alateral approach. The thermal probe 3206 can be placed in contact withor coupled to a thermally-conductive plate 3210 of the implant, eitherbefore or after the implant is inserted. Cooled or heated fluid can becirculated through the cavity of the thermal probe to apply a thermaleffect to the implant and thereby apply localized thermal therapy to theanatomy proximate thereto (e.g., the spinal canal). After completion ofthe thermal therapy, or at any other desired time, the probe can beseparated or decoupled from the implant and removed, leaving the implantin place indefinitely. Alternatively, the implant can be removed withthe probe. As described in further detail below, the patient can beclosed up with just the probe or just the inlet and outlet conduitsextending through the closed incision, such that thermal therapy can beperformed after the surgical procedure to implant the thermal device.Later, the probe can be decoupled from the device in a non-surgical orminimally-invasive procedure by simply pulling the probe through theclosed incision.

FIGS. 33A-33B illustrate an exemplary thermal device 3302. Except asindicated below, the structure and operation of the thermal device 3302is substantially identical to the thermal device 3202, and therefore adetailed description is omitted here for the sake of brevity. In thethermal device 3302, the thermally-conductive member can be formed froman ultra-thermally efficient material such as graphene. For example, oneor more side surfaces of the implant 3304 can include a strip 3310 ofone-atom-thick graphene affixed thereto or seated therein. In use, thethermal probe 3306 can be placed in contact with the graphene strip 3310to apply a thermal effect to the implant.

FIGS. 34A-34C illustrate an exemplary thermal device 3402. Except asindicated below, the structure and operation of the thermal device 3402is substantially identical to the thermal device 3202, and therefore adetailed description is omitted here for the sake of brevity. In thethermal device 3402, the thermally-conductive plate 3410 can be C-shapedsuch that the plate extends around a posterior surface 3404P of theimplant, an anterior surface 3404A of the implant, and a lateral surfaceof the implant. The thermal probe 3406 can be configured to contact orcouple to the plate 3410 at any of a variety of locations, including onthe lateral surface as shown. The thermal probe 3406 can serve as aninsertion tool for guiding and urging the implant into the disc space.In use, the implant can be coupled to the thermal probe outside of thedisc space and the thermal probe can be used to advance the implant intothe disc space. A thermal effect can then be delivered to the implantvia the thermal probe to apply localized thermal therapy to tissue inproximity to the implant (e.g., a patient's spinal canal in proximity toa plate portion of the implant).

FIGS. 35A-35C illustrate an exemplary thermal device 3502. Except asindicated below, the structure and operation of the thermal device 3502is substantially identical to the thermal device 3202, and therefore adetailed description is omitted here for the sake of brevity. In thethermal device 3502, the implant is sized and configured for deliverythrough an anterior approach, e.g., to perform an anterior cervicalinterbody fusion procedure. The device 3502 can include athermally-conductive plate 3510 that extends around three sides of theimplant (e.g., a posterior- or spinal-canal-facing side 3504P and firstand second lateral sides). Accordingly, the thermal probe can be placedin contact with or coupled to either of the lateral sides of thethermally-conductive plate 3510 while the third side of the plate isdisposed in contact with or in close proximity to the spinal canal toapply localized thermal therapy to the spinal canal.

FIGS. 36A-36E illustrate an exemplary thermal device 3602. Except asindicated below, the structure and operation of the thermal device 3602is substantially identical to the thermal device 3502, and therefore adetailed description is omitted here for the sake of brevity. In thethermal device 3602, the thermally-conductive member can be formed froman ultra-thermally-efficient material such as graphene. For example, oneor more side surfaces of the implant can include a strip 3610 ofone-atom-thick graphene affixed thereto or seated therein. In use, thethermal probe 3606 can be placed in contact with the graphene strip toapply a thermal effect to the implant.

FIGS. 37A-37C illustrate an exemplary thermal device 3702. Except asindicated below, the structure and operation of the thermal device 3702is substantially identical to the thermal device 3502, and therefore adetailed description is omitted here for the sake of brevity. In thethermal device 3702, the thermally-conductive plate 3710 extends aroundthree sides of the implant (e.g., a posterior- or spinal-canal-facingside 3704P and first and second lateral sides) such that at least aportion of the plate is exposed to an anterior-facing surface 3704A ofthe implant. Accordingly, the thermal probe 3706 can be placed incontact with or coupled to either of the lateral sides of thethermally-conductive plate 3710 at a location along the anterior-facingsurface 3704A of the implant, while the third side 3704P of the plate isdisposed in contact with or in close proximity to the spinal canal toapply localized thermal therapy to the spinal canal.

FIGS. 38A-38C illustrate an exemplary thermal device 3802. Except asindicated below, the structure and operation of the thermal device 3802is substantially identical to the thermal device 3502, and therefore adetailed description is omitted here for the sake of brevity. In thethermal device 3802, the thermally-conductive plate 3810 can besubstantially rectangular or O-shaped such that it extends around foursides of the implant (e.g., a posterior or spinal-canal-facing side3804P, an anterior side 3804A, and first and second lateral sides). Thethermal probe 3806 can be configured to contact or couple to the plate3810 at any of a variety of locations, including on the anterior surface3804A as shown. The thermal probe 3806 can serve as an insertion toolfor guiding and urging the implant into the disc space. In use, theimplant can be coupled to the thermal probe outside of the disc spaceand the thermal probe can be used to advance the implant into the discspace. A thermal effect can then be delivered to the implant via thethermal probe to apply localized thermal therapy to tissue in proximityto the implant (e.g., a patient's spinal canal in proximity to aposterior surface 3804P of the plate portion 3810 of the implant).

Pad Thermal Devices

FIG. 39A illustrates an exemplary thermal device 3902. A number ofvariations on the device 3902 are shown in FIGS. 39B-39O. The device3902 can be generally in the form pad 3904 that can be positionedadjacent to a target region of a patient to apply thermal therapythereto. The pad 3904 can have substantially rectangular shape as shownor can have any of a variety of other shapes. In some embodiments, thepad can be sized and shaped based on the anatomy that is targeted forthermal therapy. For example, the pad can have a substantially flat,rectangular shape with rounded corners and convex bottom surface sizedto conform to and fit over the exposed dura or spinal cord after alaminectomy. The pad can be positioned in contact with or in closeproximity to the dura surrounding the spinal cord. The pad can be placedover the intact lamina between the transverse and spinous processes, orcan be placed directly over the exposed dura or spinal cord after alaminectomy. The pad can also be placed over one or more spinalimplants, such that the pad covers the implants and/or is in directcontact with or in close proximity to the implants. The convex bottomsurface of the pad can be sized to receive at least a portion of thepatient's spinal cord. It will be appreciated that the pad can havevirtually any size or shape and that the size and shape can be selectedbased on various factors such as the anatomical location of the targetsite, the age, weight, species, or sex of the patient, the nature of theinjury or condition suffered by the patient, and the types of proceduresto be performed in conjunction with thermal therapy (e.g., laminectomy,vertebral fusion, and the like).

The pad 3904 can be rigid or can be resiliently or non-resilientlymalleable or deformable such that the pad 3904 can be conformed to theanatomical structures to which it is applied. In particular, the pad3904 can include a malleable membrane configured to form a substantialnegative of the anatomy against which it is placed to maximize thecontact surface area between the membrane and the anatomy.

The pad 3904 can be formed from any of a variety of materials. Exemplarymaterials include Silicone, Polyethylene terephthalate (PET), Nylon,Polyethylene (PE), Polyurethane, Polyvinyl chloride (PVC), Latex,Titanium, Steel, Gold, Cobalt Chrome, and combinations thereof.

The pad 3904 can include a cavity 3906 formed therein through whichheated or chilled fluid can be circulated to apply a thermal effect tothe device and to tissue proximate thereto. The device 3902 can includeinlet and outlet conduits 3908 configured to supply and withdraw fluid,respectively, from the cavity. The conduits 3908 can be selectivelydetachable from the pad 3904 to facilitate post-surgical withdrawal ofthe conduits. A multi-lumen conduit 3908 that includes an inlet lumenand an outlet lumen can be coupled to a proximal end of the pad 3904 asshown. Alternatively, or in addition, discrete inlet and outlet conduitscan be coupled to the pad. The conduits 3908 can be used as a tether, orthe pad 3904 can include a separate dedicated tether, such that thetether can be manipulated from outside the patient to reposition,relocate, or remove the pad.

In use, the pad 3904 can be positioned over a target treatment site of apatient (e.g., an exposed dura of a patient's spinal canal). Cooled orheated fluid can be circulated through the cavity 3906 of the pad 3904to apply localized thermal therapy to the target treatment site. Aftercompletion of the thermal therapy, or at any other desired time, theinlet and outlet conduits 3908 can be separated from the pad 3904 (e.g.,by pulling the conduits proximally) and the pad 3904 can be left inplace indefinitely. Alternatively, the pad 3904 can be removed with theinlet and outlet conduits 3908. As described in further detail below,the patient can be closed up with just the inlet and outlet conduitsextending through the closed incision, such that thermal therapy can beperformed after the surgical procedure to implant the thermal pad.Later, the fluid inlet and outlet conduits can be decoupled from the padin a non-surgical or minimally-invasive procedure by simply pulling theconduits through the closed incision. Alternatively, the fluid inlet andoutlet conduits and the pad itself can be removed together in anon-surgical or minimally-invasive procedure by simply pulling theconduits and the pad through the closed incision.

The thermal device 3902 can include one or more attachment features forcoupling the thermal device to the patient's anatomy or to one or moreancillary devices (e.g., implants, stabilization hardware, and soforth). For example, as shown in FIG. 39B, the upper surface of the padcan include one or more grooves 3910 for retaining sutures such that thepad 3904 can be sutured down to the patient's anatomy. By way of furtherexample, as shown in FIG. 39C, the pad 3904 can include an enclosed loop3912 through which a suture can be threaded to suture the pad down tothe patient anatomy.

In some embodiments, the pad 3904 can be configured to release at leasta portion of the thermal fluid supplied thereto into the surroundingsurgical site (e.g., via a controlled micro-drip). For example, as shownin FIG. 39D, the bottom surface of the pad 3904 can include one or moreholes 3914 through which thermal fluid can slowly drip to bathe thetarget treatment site with the thermal fluid. The one or more holes 3914can be arranged in a grid pattern or in any other pattern, and can bearranged to cover substantially the entire lower surface of the pad3904. Alternatively, or in addition, as shown in FIG. 39E, the one ormore holes 3914 can be formed in a distal-most or front-facing surfaceof the pad 3904 that is substantially perpendicular to the lower surfaceof the pad and that is opposite to an end of the pad to which the inletand outlet conduits 3908 are coupled. The outlet conduit can be omittedin some embodiments, particularly those in which the thermal fluid isconfigured to be released from the pad through the one or more openings.

The pad 3904 can include one or more suction or vacuum ports 3916 influid communication with an aspiration conduit. In some embodiments, theaspiration conduit and the outlet conduit of the thermal device 3902 canbe the same structure. In other embodiments, a dedicated aspirationconduit can be provided with the inlet and outlet conduits, either as aseparate discrete conduit or as a dedicated lumen within a multi-lumenconduit 3908. The suction port 3916 and aspiration conduit can beconfigured to extract excess fluid from the surgical site at which thepad 3904 is placed. For example, thermal fluid introduced into the pad3904 and released through the one or more openings 3914 can be collectedand withdrawn from the patient using the aspiration conduit. The suctionport 3916 and aspiration conduit can also be used with embodiments thatdo not release thermal fluid into the surgical site, for example toremove any extra fluid buildup that may naturally exist at the surgicalsite or be created as part of a surgical procedure ancillary to thedelivery of thermal therapy. As shown in FIG. 39F, the suction port 3916can be formed adjacent a proximal end of the pad 3904, at a junctionbetween the pad and the conduit(s) 3908. Alternatively, or in addition,the pad 3904 can include a suction port 3916 formed adjacent a distalend thereof (e.g., in a distal-facing surface of the pad), as shown inFIG. 39G.

The pad 3904 can include various features to help secure the pad to thepatient anatomy or hold the pad in a desired position with respect tothe patient anatomy. For example, as shown in FIG. 39H, the pad 3904 caninclude first and second wings 3918 that extend laterally-outwardtherefrom. The wings 3918 can be fixed to the patient anatomy usingsurface tension or natural coagulation of blood present in the surgicalsite. Alternatively, or in addition, the wings 3918 can be attached tothe patient anatomy using an adhesive (e.g., a temporary andminimum-strength adhesive gel). The wings 3918 can also include openingsformed therein through which a suture or other fastener can be applied.As shown in FIG. 39I, the pad 3904 can include a unitary C-shaped wing3918 that extends outward from the lateral sides of the pad and from thedistal-facing surface of the pad. The wings 3918 can be formed from anyof a variety of materials, including polymers, elastomers, etc.

In some embodiments, as shown in FIGS. 39J and 39K, the pad 3904 can beformed from upper and lower shells 3904A, 3904B that define the cavity3906 therebetween. The shells can be rigid or flexible. In someembodiments, the upper shell 3904A can be thermally-insulated and thelower shell 3904B can be thermally-conductive so as to focus the thermaleffect towards the lower surface of the pad 3904 which is disposedadjacent the target anatomy. The fluid inlet and outlet conduits 3908can be coupled to the pad 3904 at a proximal end thereof, or at anyother location on the pad. For example, as shown in FIGS. 39L and 39M,the inlet and outlet conduits 3908 can be coupled to the pad 3904substantially in the center of the upper surface of the pad. The inletand outlet conduits 3908 can be concentric tubes as shown or can bediscrete, non-concentric conduits.

The fluid inlet and outlet conduits 3908 can extend from the pad 3904 atan oblique angle or at any of a variety of other angles. For example, asshown in FIG. 39O, the inlet and outlet conduits 3908 can extend alongan axis that is parallel to a longitudinal axis of the pad 3904.

FIGS. 40A-40C illustrate an exemplary thermal device 4002. The device4002 can be generally in the form pad 4004 that can be positionedadjacent to a target region of a patient to apply thermal therapythereto. The pad 4004 can have substantially rectangular shape as shownor can have any of a variety of other shapes. In some embodiments, thepad can be sized and shaped based on the anatomy that is targeted forthermal therapy. The pad can be positioned in contact with or in closeproximity to the dura surrounding the spinal cord. The pad can be placedover the intact lamina between the transverse and spinous processes, orcan be placed directly over the exposed dura or spinal cord after alaminectomy. The pad can also be placed over one or more spinalimplants, such that the pad covers the implants and/or is in directcontact with or in close proximity to the implants. It will beappreciated that the pad can have virtually any size or shape and thatthe size and shape can be selected based on various factors such as theanatomical location of the target site, the age, weight, species, or sexof the patient, the nature of the injury or condition suffered by thepatient, and the types of procedures to be performed in conjunction withthermal therapy (e.g., laminectomy, vertebral fusion, and the like).

The pad 4004 can include a length of tubing 4006 and a substrate 4008.The tubing 4006 can be looped, coiled, snaked, wound, etc. to define theoverall shape of the pad 4004. While a generally rectangular pad shapeis shown, it will be appreciated that the tubing can be positioned inany of a variety of patterns to form any of a variety of shapes. In theillustrated embodiment, the tubing 4006 is looped such that two freeends 4006A, 4006B of the tubing extend proximally away from thesubstrate 4008 (e.g., through a substantially closed skin incision to alocation exterior to the patient).

The substrate 4008 can be a planar sheet to which the tubing 4006 isadhered or otherwise coupled. The substrate 4008 can also be athree-dimensional form in which the tubing 4006 is suspended orencapsulated. The substrate 4008 can be formed from a biodegradable orbioabsorbable material that is configured to dissolve when the device4002 is disposed in a surgical site within a patient after apredetermined time has elapsed. Exemplary materials from which thesubstrate 4008 can be formed include polymers such as poly-L lactic acid(PLLA), polyglycolic acid (PGA), polylactic acid (PLA), and combinationsthereof. As the substrate 4008 dissolves, the tubing 4006 can becomefree to unwind or uncoil to facilitate removal of the tubing through asubstantially closed skin incision. In other words, with the substrate4008 no longer holding the tubing 4006 in the wound or coiledconfiguration, pulling the free ends 4006A, 4006B of the tubingproximally can cause the loop of tubing to straighten out into a singleelongate loop that can be easily removed through a narrow passageway.

The tubing 4006 can define a fluid path through which heated or chilledfluid can be circulated to apply a thermal effect to the device 4002 andto tissue proximate thereto. The free ends 4006A, 4006B of the tubing4006 can define inlet and outlet conduits configured to supply andwithdraw fluid, respectively, from the looped or coiled portion of thetubing.

In use, the pad 4004 can be positioned over a target treatment site of apatient (e.g., an exposed dura of a patient's spinal canal). Thesubstrate 4008 can be allowed to biodegrade or dissolve at the treatmentsite over a predetermined period of time. Cooled or heated fluid can becirculated through the tubing loop 4006 to apply localized thermaltherapy to the target treatment site. After completion of the thermaltherapy, or at any other desired time, for example after the substrate4008 dissolves, the free ends 4006A, 4006B of the tubing loop can bepulled proximally to uncoil the loop of tubing and pull the tubing 4006out of the patient. As described in further detail below, the patientcan be closed up with just the free ends of the tubing extending throughthe closed incision, such that thermal therapy can be performed afterthe surgical procedure to implant the thermal device. Later, the devicecan be removed from the patient in a non-surgical or minimally-invasiveprocedure by simply pulling the loop of tubing through the closedincision.

FIGS. 41A-41C illustrate an exemplary thermal device 4102. Except asindicated below, the structure and operation of the thermal device 4102is substantially identical to the thermal device 4002, and therefore adetailed description is omitted here for the sake of brevity. In thethermal device 4102, the length of tubing 4106 can include pluralinterior lumens. For example, the tubing 4106 can be formed from aco-extrusion that includes first and second interior lumens 4110, 4112which can act as fluid inlet and fluid outlet lumens, respectively. Thelength of tubing 4106 can include a first proximal free end 4106A and asecond distal free end 4106B. The distal free end 4106B of the tubingcan be closed and can include a small cavity or crossover to place thedistal end of the inlet lumen 4110 in fluid communication with thedistal end of the outlet lumen 4112. The tubing 4106 can thus be loopedor coiled such that only a single free end 4106A of the tubing extendsproximally from the device (e.g., to a location outside of the patient).When the device 4102 is to be removed from the patient, only a singlestrand of the tubing 4106 needs to be pulled through the incision, thusallowing for a smaller profile than embodiments in which the tubing islooped as it is pulled through simultaneously.

Misc Device Features

As noted above, the thermal devices disclosed herein can include aninner reservoir or chamber. The chamber can house at least a portion ofthe elements, volumes, nozzles, fluid lumens, channels, paths, and soforth needed to support the cooling means. In implementations in whichthe cooling means includes expanding gas, the thermal device can includean expansion nozzle through which gas that has entered the thermaldevice via a cooling delivery conduit expands. The gas is expanded intothe chamber, from which it can be exhausted from the thermal device viaan exhaust conduit. The expanded gas can be exhausted into theenvironment, into a chamber or tank, or into a compressor whichre-compresses it.

In implementations in which the cooling means is a chilled fluid, thefluid can be passed through the inner chamber of the thermal device todeliver a cooling effect thereto and to surrounding tissue. In someembodiments, the chamber can be in the form of a fluid lumen having afirst end coupled to a delivery conduit and a second end coupled to anexhaust conduit. The chamber/fluid lumen can optionally be coiled,snaked, or formed in some other tortuous, surface-area maximizing shapesuch that heat exchange to/from fluid that is directed through thechamber can be optimized. The fluid can also simply enter the chamberthrough a delivery conduit, reverse direction, and exit the thermaldevice through an exhaust conduit.

In implementations in which the cooling means is a Peltier device, thePeltier device can be embedded inside the thermal device and electricallines can be connected to the Peltier device internal to the thermaldevice. These electrical lines can extend from the thermal device to apower source and optionally a regulator of the cooling effect, which canregulate the voltage or current on the electrical lines. In someembodiments, the power source and/or regulator can be disposed on or inthe thermal device or in a separate implantable unit.

The thermal device can optionally include a plurality of thermal finsformed within the chamber. For example, the thermal fins can extendradially inward from an outer wall of the chamber. In use, an expandedgas or chilled fluid can circulate around and across the thermal fins,which can improve the thermal conduction from the cooling means to thethermal device, and thus to the target tissue. The thermal fins can alsoimprove the mechanical strength of the thermal device. It will beappreciated that the thermal fins can be oriented in a variety ofdirections and can take on a variety of shapes and sizes.

The delivery conduit can extend well into the chamber, terminating at alocation adjacent to a distal end of the chamber. The exhaust conduit,on the other hand, can terminate only a small distance into the chamber,adjacent to the proximal end thereof. With this relative positioning ofthe conduit outlets, fluid introduced through the delivery conduit mustflow through substantially the entire length of the chamber before beingremoved through the exhaust conduit. In this manner, the thermaltransfer between the fluid and the thermal device can be maximized andmore evenly distributed along the heat exchanging surfaces of thethermal device. In some embodiments, the chamber and/or the deliveryconduit can extend only along discrete portions of the device wherecooling is desired.

In some embodiments, the delivery conduit can be helically wound aroundthe perimeter of the chamber. This can advantageously improve thermaltransfer between the delivery conduit and the thermal device. Inaddition, the delivery conduit can act as an internal baffle, routingfluid released from the distal end of the delivery conduit along ahelical path back towards the exhaust conduit. Thus, thermal transfercan also be improved between fluid released from the delivery conduitand the thermal device.

Portions of the thermal device other than the regions to be placedagainst the target anatomy can be coated with a thermally insulatingmaterial, such that the cooling effect is focused at the target site,such that surrounding tissue is protected from the cooling effect, andsuch that a surgeon or other user holding the device is protected fromthe cooling effect. Exemplary thermally insulating materials includesilicone, which can be spray coated onto the device.

It will be appreciated that the devices and hardware described hereinare able to be produced using common practices known to those skilled inthe art of hardware manufacturing and specifically surgical devicemanufacturing.

Methods

The thermal devices disclosed herein can be used in any of a variety ofassociated methods. Various examples of such methods are describedbelow. It should be noted that any ordering of method steps implied bythe following is not to be construed as limiting the method toperforming the steps in that order. Rather, the various steps of each ofthe methods disclosed herein can be performed in any of a variety ofsequences. In addition, as the described methods are merely exemplaryembodiments, various other methods that include additional steps orinclude fewer steps are also within the scope of the present invention.Furthermore, two or more of the method steps can be performedsimultaneously.

Before beginning a surgical procedure, a surgical plan can be developed,for example using pre-operative imaging of the site that is targeted forthermal therapy (e.g., cooling and/or heating). A thermal device havingan appropriate type, size, shape, etc. can be selected as part of thesurgical plan, or can be selected in real-time during the actualsurgery. As detailed above, the particular thermal device to be used canbe selected based on a variety of factors.

Access to the target site can be obtained using various knowntechniques. For example, a tissue opening can be formed using an opensurgical technique (e.g., one in which skin, fat, muscle, connectivetissue, etc. overlying the surgical site is incised and retracted). Atissue opening can also be formed using a minimally-invasive surgicaltechnique (e.g., one in which a percutaneous access device is used toform a portal between the patient's skin surface and the target site).

Various steps can be performed to prepare the target site for thermaltherapy. For example, in the case of a traumatic spinal cord injury, adecompression procedure (e.g., partial or complete laminectomy) can beperformed at one or more vertebral levels. By way of further example,the site can be prepared by decorticating bone in the vicinity of thetarget site. Thus, in the case of a spinal procedure, the surfaces ofthe lamina, spinous process, and/or facets can be decorticated.

Various ancillary or related procedures can be performed at the targetsite before or after initiating thermal therapy. For example, a spinalfusion procedure or a procedure to install spinal stabilization hardwarecan be performed.

The steps involved in placing the thermal device and applying thermaltherapy therewith vary depending on the type of thermal device that isused. Placement of the thermal device can include conforming the deviceto the target anatomy. Correct placement of the device can be verifiedvisually or using fluoroscopy or other imaging techniques.

Thermal therapy can be applied through the device, for example bycirculating a chilled fluid through the device. Embedded sensors can beused to monitor various parameters of the patient or operatingenvironment, and the thermal therapy can be modulated based on theoutput of the sensors. For example, the temperature and/or flow rate offluid circulated through the device can be adjusted to maintain adesired temperature. Where only intraoperative therapy is desired, thedevice can be removed once the desired duration of thermal therapy hasbeen applied and the tissue opening can be closed. Where postoperativetherapy is desired, the thermal device and one or more conduits can beleft in place and the tissue opening can be closed. The one or moreconduits can be left exposed, extending through the closed tissueopening. The one or more conduits can also be left buried beneath thepatient's skin, where they are readily accessible in aminimally-invasive follow on procedure to conduct additional thermaltherapy or to remove the one or more conduits. In either case, theconduits can be sutured or otherwise secured to prevent excessivemovement. Postoperative thermal therapy can be delivered through the oneor more conduits for an extended period, as described in more detailbelow. When the capability to deliver additional thermal therapy is nolonger desired, the one or more conduits can be removed (e.g., bypulling them proximally to withdraw them from the patient). The thermaldevice can be left implanted permanently, and can optionally beconfigured to be bioabsorbed by the patient over time. Alternatively,the thermal device can be removed with the conduits or in a separateprocedure.

FIG. 42 illustrates a method of applying thermal therapy to tissue. Instep S4200, a tissue opening is formed. A thermal device is placed at atarget site in step S4202 and the tissue opening is closed in stepS4204. After closing the tissue opening, thermal therapy is delivered tothe target site via the thermal device in step S4206. Thermal therapycan also be initiated or delivered via the thermal device prior toclosing the tissue opening in step S4204, and can be continued orre-started in step S4206 after closing the tissue opening. FIG. 43illustrates a method of applying thermal therapy to tissue. In stepS4300, a target site is accessed. The target site is prepared in stepS4302, and thermal therapy is applied to the target site via a thermaldevice in step S4304.

The thermal device can be left implanted for any amount of time (e.g.,at least about 1 hour, at least about 4 hours, at least about 12 hours,at least about 18 hours, at least about 24 hours, at least about 48hours, at least about 72 hours, at least about 5 days, at least about 7days, at least about 2 weeks, at least about 1 month, at least about 3months, at least about 6 months, at least about 1 year, at least about 5years, at least about 10 years, and/or permanently or indefinitely.

Hypothermia Delivery—Temperature & Time

The methods and devices described herein can generally involve applyinglocalized therapeutic hypothermia and, in some cases, cooling the tissuein and around the spinal cord. Various hypothermic instrumentations aredescribed to deliver a cooling effect to the spinal canal, and to thespinal cord itself. “Therapeutic hypothermia” as used herein refers tothe reduction of tissue temperature below a patient's normal bodytemperature, typically about 37 degrees C. Therapeutic hypothermia canalso include reduction of tissue temperature below a patient's bodytemperature when treatment is initiated, which may not be the patient'snormal body temperature (e.g., when the patient presents with a fever orin an already-hypothermic state, for example due to previous or ongoingsystemic hypothermia treatment).

The degree of hypothermia applied can vary upon a number of factors.Target therapeutic temperatures can range from just below 0 degrees C.to just below normothermia. Tissue exposure to temperatures below 0degrees C. can lead to cellular damage, however the bones of the spinalcolumn are relatively resilient to such low temperatures and thereforetarget therapeutic temperatures can be below 0 degrees C. in someembodiments.

In an exemplary embodiment, the target tissue is cooled to within arange of about 0 degrees C. to about 37 degrees C. The target tissue canalso be cooled to within a range of about 5 degrees C. to about 36degrees C., more preferably about 15 degrees C. to about 36 degrees C.,more preferably about 25 degrees C. to about 36 degrees C., morepreferably about 25 degrees C. to about 35 degrees C., and morepreferably about 30 degrees C. to about 34 degrees C. In certainembodiments, the target tissue can be cooled to about 36 degrees C.,about 35 degrees C., about 34 degrees C., about 33 degrees C., about 32degrees C., about 31 degrees C., or about 30 degrees C. In otheraspects, the target tissue can be cooled to about 1 degree C. belownormothermia, about 2 degrees C. below normothermia, about 5 degrees C.below normothermia, about 10 degrees C. below normothermia, or about 20degrees C. below normothermia.

Degrees of hypothermia are sometimes described in terms of “mild”hypothermia (e.g., 0-5 degrees C. below normothermia), “moderate”hypothermia (e.g., 5-9 degrees C. below normothermia), “severe”hypothermia (e.g., 9-17 degrees C. below normothermia), and “profound”hypothermia (e.g., more than 17 degrees C. below normothermia). Themethods disclosed herein can include cooling of tissue to within any ofthese ranges, and the systems and devices disclosed herein can beconfigured to achieve such cooling. Various treatment protocols can alsobe used in which the tissue temperature is cycled, pulsed, swept,ramped, and/or stepped through these or other ranges. For example, inone treatment method, the tissue temperature can be quickly lowered to atarget temperature and then slowly ramped back up to normothermia whenit is desired to cease treatment. By way of further example, the tissuetemperature can be slowly stepped down to a first target temperature,oscillated between the first target temperature and a second targettemperature, and then eventually stepped back up to normothermia.

The duration of exposure of the target tissue to the cooling effect canrange from minutes to days, weeks, months, or years depending on avariety of factors, including the patient's condition, the treatment ofthe patient's other injuries, the prospective treatment protocol for thepatient, and monitored or detectable physiological responses, or lackthereof, to the cooling. Therapeutic hypothermia can be applied in asingle procedure or multiple times. In either case, a multiplicity ofdifferent temperatures can be applied. Preferably, when discussingtarget temperatures, it is intended to mean the desired therapeutictemperature of the targeted tissue. Alternatively, target temperature attimes can also refer to the temperature of the thermal device or thecooling chamber or element of the thermal device. It will be appreciatedthat it can be necessary in some instances to cool the thermal device tobelow the target tissue temperature in order for the target tissue toreach the target tissue temperature.

The methods described herein can include cooling the spinal canal tissueand the spinal cord for variable lengths of time and/or at differenttemperatures. In addition, cooling can occur in multiple doses, whereeach dose can differ from the others in exposure time and/ortemperature. The determination of the exposure time(s) andtemperature(s) can be predetermined based on known effective times andtemperatures or can be determined based on the condition of the patientand/or when the treatment is applied relative to when the injuryoccurred. A wide variety of physiological effects, both local andsystemic, can arise from the cooling of the target tissue (e.g., spinalcanal tissue and the spinal cord) below normal body temperature.Exposure time, doses, and target temperature can be varied during theprocedure based on monitored physiological parameters or characteristicsas well as parameters of the cooling devices or systems.

These parameters include, but are not limited to, neurological findings,blood pressure, target-tissue temperature, specific tissue temperature(proximate to target tissue), core (rectal) body temperature, venousblood temperature near or exiting target tissue, pulmonary conditions,cardiac conditions, sensory evoked potentials (SEPs, includingsomatosensory evoked potentials), motor-evoked potentials (MEPs),intrathecal pressure, perfusion pressure, levels of blood oxygen &glucose, ATP concentrations, markers of excitotoxicity, vasogenic edema,apoptosis, inflammation, and enzymatic responses. The targettemperature, doses, and exposure time can be selected by initialmeasurements of these physiological parameters and then modified basedupon real-time measurement of these parameters. Effectively, the coolingregimen, in terms of temperatures, exposure times, and doses, can becontrolled by measured physiological characteristics of the patient andthe cooling devices and systems.

For example, a cooling effect can be applied initially at apredetermined target temperature based on the type and severity ofinjury incurred, including for example the vertebral level of injury.The cooling effect can be increased, and as such, the target temperaturecan be reduced, if after a predetermined period of time, themotor-evoked potential responses of the patient appear unremarkable. Inone embodiment, if the difference between the arterial blood pressureand the cerebral spinal fluid pressure reduces below a predeterminedthreshold, the application of the therapeutic hypothermia can bestopped. It should be understood that there are any number of protocolsthat can be followed in the application of therapeutic hypothermia basedon clinical, laboratory, and monitoring markers.

In some embodiments, therapeutic hypothermia is initiated as soon aspossible following a spinal injury, e.g., less than 8 hours after theinjury. Therapeutic hypothermia can be maintained up to 72 hours, up to120 hours, or more. It can be desirable to deliver therapeutichypothermia for a much shorter duration as well, including as little asa fraction of an hour (e.g., 5 minutes, 15 minutes, 30 minutes, or 45minutes).

The use of therapeutic hypothermia on the spinal cord and the spinalcanal can yield a variety of beneficial effects. Such effects caninclude the reduction of nervous tissue metabolic demand, excitotoxicmarkers, apoptosis, free-radicals, and inflammation. It should be notedthat some of the mechanisms of action associated with therapeutichypothermia are not fully understood, but experience with itsapplication in a variety of clinical situations suggests a mitigatingeffect in spinal cord damage from trauma, vascular insult, or surgicalinsult.

Transosseous Cooling

In some of the methods and devices described herein, a cooling effect isapplied transosseously, or through bone. In particular, tissue can becooled by positioning a thermal device in or over adjacent or nearbybone or over an implant implanted in adjacent or nearby bone. Bone hasproperties that make it an advantageous cooling platform. Boneystructures are readily locatable due to their greater density andrigidity than so-called soft tissues. Furthermore, their geometries arereadily mapped radiographically, are relatively consistent betweenpatients, and have easily locatable features or landmarks. Accordingly,particular surrounding or soft tissues are relatively consistentlylocated in a known proximity to these bone structures and landmarks. Inparticular, vertebral pedicles and lamina lie in close proximity to thecontents of the spinal canal, including the spinal cord and nerve roots.

These attributes allow specific surrounding soft tissue to be reliablytargeted by using adjacently located bone structures and landmarks ofthe bone structures as a platform and avenue to put devices near thespecific soft tissue. Using bony structures and their landmarks as ameans for targeting nearby or adjacent tissues helps avoid a need todirectly target the tissue wishing to be treated, leaving the tissueundisturbed.

An advantageous aspect of a transosseous approach for providing acooling effect to nearby soft tissue is the fact that bone is rigid,allowing for an device to be securely anchored into or on the bone,where the bone is not subject to deformation because of bodily movementor because of the device's presence. The rigid nature of the bone alsoallows a thermal device applied or anchored thereto without disturbingthe tissues outside of the bone.

A transosseous approach for providing a cooling effect to nearby softtissue allows for the implantation of thermal instrumentation withoutdisturbing the soft tissue itself. That is, by using a bone approach andcooling across the bone wall to the nearby tissue, the targeted nearbytissue is not physically touched, displaced, or incised by the thermaldevice or by the surgical steps needed to implant the thermal device.Certain tissues, such as spinal cord tissue, are delicate and sensitiveto disturbances, and such disturbances could cause permanent injury tothe tissues. As such, it can be undesirable to implant thermal devicesin these tissues or in nearby soft tissues due to risks of causinginjury to the tissues. Bone is very resilient to such disturbances, andtypically does not realize a great loss in function or strength and istypically not susceptible to long term injury from such disturbances. Itis therefore desirable to apply or affix a thermal device to a bonystructure and cool nearby soft tissue transosseously, or across the bonewall, thus allowing for reliable cooling access to soft tissue withoutphysically disturbing the soft tissue itself.

In exemplary embodiments, the soft tissue that is targeted to be cooledis the spinal cord, other spinal canal tissue, and/or nerve root tissue,and the bony structures which act as the cooling platform are parts of avertebra, including the elements of the posterior arch such as thepedicles, the lamina, and the spinous process. A transosseous approachfor providing cooling across pedicle and/or lamina bone to the adjacentspinal canal contents targets the spinal cord without its actualcontact, displacement, or penetration. This can be a criticalconsideration since the spinal cord's tolerance for such intrusions islikely minimal. In some embodiments, however, particularly those inwhich a decompression procedure is performed, the thermal devices can beplaced in direct contact with the spinal cord or the dura.

Concluding Statements

It will be understood that any of the methods and devices disclosedherein can be used on multiple vertebrae at once and/or multiple bonystructures of each vertebra at once, by utilizing multiple thermaldevices at the same time or a single, larger thermal device. It will beunderstood that the methods and devices disclosed herein can be used forconditions other than traumatic spinal cord injury, including forcooling other tissues. The methods and devices can be used for othertypes of spinal cord injury, as well as for treating nerve root damage.The methods and devices can be used prophylactically. The methods anddevices can be used before, during, and/or after an injury occurs andcan be used pre-operatively, peri-operatively, intra-operatively and/orpost-operatively with regard to any particular procedure that can beconducted.

Furthermore, the methods and devices can be used for non-injury relatedpurposes. In particular, the methods and devices described herein can beused as an adjunctive procedure to an aneurysm repair surgery, such asthoracoabdominal aortic aneurysm repair or abdominal aortic aneurysmrepair. In these procedures, it is common for blood flow to the spinalcord to be compromised, thus introducing a risk of ischemic spinal cordinjury. The methods and devices described herein can provide aprotective therapy during such ischemic periods.

Further, the methods and devices described herein can also be used forspinal fusion procedures where cooling is not initially intended. Themethods and devices described herein can be used for fusion with theunderstanding that an intraoperative complication can occur (example:iatrogenic injury caused during scoliosis correction surgery) wherehaving the capability to deliver a cooling effect can be desired.

The methods and devices described herein can be used prophylactically todeliver a cooling effect to nerve roots. Though such delivery of acooling effect can be achieved with one thermal device, it can be betterachieved by having two or more thermal devices placed above and belowthe particular root that is being targeted. The delivery of a coolingeffect to a nerve root can also occur peri-operatively orpost-operatively.

It will be appreciated that the methods and devices disclosed herein canbe used in other parts of a mammalian body, and in particular, can beused with orthopedic procedures to deliver a cooling effect tosurrounding tissues.

The described aspects above are given as illustrative examples of thosethat fall within the scope of the subject matter described, but are notintended to limit that scope. The described devices and methods can bethe sole devices and methods used and performed in the spine at the timeof the herein described therapy or can accompany other devices andprocedures such as those related to spinal decompression, reduction,stabilization, and fusion.

The devices disclosed herein can be designed to be disposed of after asingle use, or they can be designed to be used multiple times. In eithercase, however, the device can be reconditioned for reuse after at leastone use. Reconditioning can include any combination of the steps ofdisassembly of the device, followed by cleaning or replacement ofparticular pieces, and subsequent reassembly. In particular, the devicecan be disassembled, and any number of the particular pieces or parts ofthe device can be selectively replaced or removed in any combination.Upon cleaning and/or replacement of particular parts, the device can bereassembled for subsequent use either at a reconditioning facility, orby a surgical team immediately prior to a surgical procedure. Thoseskilled in the art will appreciate that reconditioning of a device canutilize a variety of techniques for disassembly, cleaning/replacement,and reassembly. Use of such techniques, and the resulting reconditioneddevice, are all within the scope of the present application.

Preferably, the devices described herein will be processed beforesurgery. First, a new or used device is obtained and if necessarycleaned. The device can then be sterilized. In one sterilizationtechnique, the device is placed in a closed and sealed container, suchas a plastic or TYVEK bag. The container and its contents are thenplaced in a field of radiation that can penetrate the container, such asgamma radiation, x-rays, or high-energy electrons. The radiation killsbacteria on the device and in the container. The sterilized device canthen be stored in the sterile container. The sealed container keeps thedevice sterile until it is opened in the medical facility.

Further details on methods and devices for cooling tissue, includingmethods and devices which can be used in conjunction with thosedescribed herein, are discussed in U.S. Pat. No. 8,523,930 issued onSep. 3, 2013, entitled “METHODS AND DEVICES FOR COOLING SPINAL TISSUE”;U.S. Pat. No. 8,721,642 issued on May 13, 2014, entitled “TISSUE COOLINGCLAMPS AND RELATED METHODS”; and U.S. application Ser. No. 14/276,265filed on May 13, 2014, entitled “IMPLANTABLE DEVICES FOR THERMAL THERAPYAND RELATED METHODS”; which are each hereby incorporated by referenceherein in their entirety.

The foregoing description has been presented for purposes ofillustration and description. Many modifications and variations of thesubject matter described will be apparent to those skilled in the art.Although the invention has been described by reference to specificembodiments, it should be understood that numerous changes can be madewithin the spirit and scope of the inventive concepts described.Accordingly, it is intended that the invention not be limited to thedescribed embodiments, but that it have the full scope defined by thelanguage of the following claims.

1.-15. (canceled)
 16. A method of applying localized thermal therapy toa patient, the method comprising: forming a bone hole in a bonestructure of the patient; seating a non-threaded cylindrical distalprojection of a bone plug into the bone hole, wherein the bone plugincludes a chamber formed therein, a delivery conduit in fluidcommunication with the chamber, and an outlet conduit in fluidcommunication with the chamber; and delivering a thermal medium throughthe delivery conduit to the chamber to apply a thermal effect to thebone plug and apply localized thermal therapy to the bone structure andtissue adjacent thereto.
 17. The method of claim 16, wherein theadjacent tissue comprises neural tissue.
 18. The method of claim 16,wherein the adjacent tissue comprises a spinal canal.
 19. The method ofclaim 16, wherein the delivery conduit and the outlet conduit are eachdetachable from the bone plug.
 20. The method of claim 19, furthercomprising closing an incision through which the bone plug is insertedaround the delivery conduit and applying the thermal effect to the boneplug after closing the incision.
 21. The method of claim 20, furthercomprising removing the delivery conduit and the outlet conduit from thebone plug after delivering the thermal medium by pulling the deliveryconduit proximally through the closed incision and pulling the deliveryconduit out of the patient through the closed incision.
 22. The methodof claim 21, wherein the bone plug remains inside the patient afterremoval of the delivery conduit and the outlet conduit.
 23. The methodof claim 21, further comprising removing the bone plug from the patientafter or during removal of the delivery conduit and the outlet conduit.24. The method of claim 20, further comprising removing the bone plugfrom the patient by pulling the delivery conduit proximally through theclosed incision and pulling the delivery conduit, the bone plug, and theoutlet conduit out of the patient through the closed incision.
 25. Amethod of applying localized thermal therapy to a patient, the methodcomprising: implanting a bone anchor into a bone structure of thepatient, wherein the bone anchor includes a fluid inlet pathway and afluid outlet pathway; attaching a connector having a fluid deliveryconduit and a fluid exhaust conduit to the bone anchor to place thefluid delivery conduit in fluid communication with the fluid inletpathway and the fluid exhaust conduit in fluid communication with thefluid outlet pathway; and circulating a cooled or heated fluid throughthe bone anchor via the connector such that the fluid enters the boneanchor through the fluid delivery conduit and exits the bone anchorthrough the fluid exhaust conduit to apply a thermal effect to the boneanchor, the bone structure of the patient, and tissue adjacent to thebone structure of the patient.
 26. The method of claim 25, whereinattaching the connector comprises attaching the connector to a headportion of the bone anchor such that a distal-facing surface of theconnector abuts a proximal facing surface of the head portion of thebone anchor.
 27. The method of claim 25, wherein circulating the cooledor heated fluid through the bone anchor comprises circulating the fluidthrough a proximal head portion of the bone anchor.
 28. The method ofclaim 25, wherein attaching the connector comprises seating theconnector in a recess formed in the bone anchor such that the fluiddelivery conduit and the fluid exhaust conduits extend through at leastone cut-out formed in the bone anchor beneath a rod-receiving recessdefined in the bone anchor.
 29. The method of claim 28, furthercomprising seating a spinal fixation element in the rod-receiving recessafter attaching the connector.
 30. The method of claim 25, whereinattaching the connector comprises seating the connector such that adistal projection of the connector forms a seal with a cannulation ofthe bone anchor and first and second lateral extension of the connectorare seated with a rod-receiving recess of the bone anchor.
 31. Themethod of claim 25, further comprising closing a skin incision throughwhich the bone anchor is implanted in the patient such that the fluiddelivery conduit and the fluid exhaust conduit extend through theincision and, thereafter, circulating the fluid.
 32. The method of claim31, further comprising closing the incisions and, thereafter, detachingthe connector from the bone anchor and removing the connector from thepatient without re-opening the incision.
 33. The method of claim 25,further comprising using the connector to manipulate the position of thebone structure prior to, during, or after circulating the fluid.
 34. Themethod of claim 25, further comprising delivering an implant through theconnector prior to, during, or after circulating the fluid.
 35. Themethod of claim 34, wherein the implant comprises a fixation rod andwherein the method further comprises coupling the fixation rod to thebone anchor.